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- Special Edition Using Visual Basic Script -

Appendix A - History of the Internet

Rather than plow into a long, boring dissertation on dates (it all startedin 1969) and names (Defense Advanced Research Projects Agency started itall, and it's been know as, and comprised of, DARPANET, ARPANET, MILNET,NSFNET, and Merit at one time or another), let's take a look at what theInternet was, is, and will become.

When it all began, the idea was simple: create a very fault-tolerantnetwork of military computers. By completely decentralizing administrationand control, and by providing automatic routing over multiple paths, thesystem would be able to withstand everything from minor localized outagesall the way up to nuclear war.

From that humble beginning (there were initially only a handful of largecomputers "on the Net"), today we have a massive network-of-networks,growing at such a phenomenal rate that providing any usage figures wouldbe meaningless by the time you read this book.

Originally, the network was used to transfer data from one large facilityto others. Personal computers would not be available for a decade, andwidespread usage would take even longer. The Internet was the playgroundof the lucky few, and the elite. Mere mortals need not apply.

Those of us on "the outside" would occasionally see tantalizingglimmers of it in magazine articles, or hear words like "UseNet"and "e-mail" from friends with accounts on large university mainframes.However, getting "on the Net" was simply not possible for mostof us.

One of the first avenues of Net access for non-insiders was a systemcalled "The Cleveland Free-Net," which was created by CWRU (CaseWestern Reserve University) using Freeport software that they developed.Within a few years, numerous "Free-Nets" appeared all over thecountry, providing local residents basic access to the Internet. They coulduse e-mail, browse Gophers, access UseNet newsgroups, local community newsand events, and more.

Other providers also began offering Internet access, but by and largeusers faced an intimidating obstacle: however nifty the concept was, itnever got far from its UNIX roots. Users worked with character-based shellsthat ran over the UNIX operating system. This meant no graphics, no buttonsto click, scrollbars to slide, boxes to check, or menus to pull down. Creatinge-mail required use of a UNIX text editor and complex commands. In short,it was not for the faint of heart.

For this type of access, users dialed up with a terminal program, andwhatever Internet host they dialed behaved like a sort of super-BBS system.As great as it all was, there were sufficient built-in limitations to restrictit to the few brave souls who were willing to put up with the difficulties.

Two things brought us where we are today: the Winsock API and the WWW.Winsock is a protocol stack that provides a layer that creates a link betweenInternet applications and the Internet itself. Before the creation of Winsock,there were a few approaches to TCP/IP access on PCs, but they were difficultto use, and installation and setup was tantamount to a black art. Winsockprovided a consistent platform that developers could write for, and writethey did.

Applications like Telnet, FTP, Finger, e-mail, IRC and talk programs,newsreaders, and so forth were quickly made available for free downloadat FTP sites all over the world. These programs, when run over a Winsocklink, made each user's computer a station on the Internet, just like anyother site. Suddenly, dial-up UNIX hosts became functionally obsolete;users could send e-mail by clicking a button and typing in a convenientWindows text box, rather than learn a crude remote UNIX editor. They couldbrowse newsgroups while downloading files, and receive e-mail at the sametime. (Winsock allows multitasking, in effect, giving each running applicationits own virtual modem.)

About this time (the early '90s), the WWW started taking off. Applicationslike Mosaic created the capability to "browse the Web" and seea mix of text and graphics, all tied together with hypertext style links.This created the current wave of interest in the Internet, and the demandfor access spurred numerous small companies to start provider services.

You Are Here

At this point in the rapidly developing history of the Internet, the"big boys" are getting into the ISP (Internet Service Provider)game. Everyone from CompuServe to telephone companies to cable TV operatorsare becoming ISPs. Internet access is rapidly becoming a commodity, andnearly everyone is within a local call of a dial-up modem pool at a reasonableprice.

Today, access is ubiquitous. The Internet is no longer the exclusiveprovince of the propeller-beanie and pocket-liner crowd. The next wavewill not be one of access, but of content. For all its popularity, theWWW is essentially a one-way, static medium. It's sort of like televisionfor computers. Now, with tools like VBScript, Web pages can easily be providedactive content. The personal communications systems that have been predictedfor years may very well arrive on the scene as little-more than wirelessbrowsers of an active-content-rich WWW.

Learning the concepts presented in this book will place you in the rightplace at the right time to position yourself to capitalize on the nextmajor growth stage of the Internet. It's a good time to know Visual Basic.

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- Special Edition Using Visual Basic Script -

APPENDIX B - HTML Reference

This appendix covers all the HTML elements (or tags) supported by thecurrent version of Internet Explorer (3.0 beta 1). This appendix is looselybased on the HTML 3.2 Standard and the Internet Explorer 3.0 documentationavailable with the Internet Software Development Kit (SDK). Examples demonstratingthe syntax of the HTML tags are shown at the end of each section. Severalof the elements are standard HTML, while others are not and may changeconsiderably in subsequent versions of Internet Explorer.

The appendix is organized into four major sections. The first containselements that are used with the header portion of an HTML page. The secondsection contains elements that are used with the body portion of an HTMLpage; the third section contains miscellaneous tags and a brief glossaryon HTML terminology. The final section contains a full list of supportedcolor names used by Internet Explorer. Special sections are given to client-sideimage maps, lists, frames, tables, forms, and objects since they containseveral sub-attributes and elements.

Header Tags

The Tag

Purpose

The tag is what specifies the header portion of the document.It is within the tags that all the information describingthe document should be placed. A header should exist if you plan to giveyour document a title, using external style sheets, or incorporating otherbits of miscellaneous information that doesn't relate to the content ofthe page.

The New HTML 3.2 Standard implies that the header section does not necessarilyhave to exist for header information, scripts, and style formats.

Syntax

...

Attributes

None.

Example

This is the title of the document and appears in the

[ccc] title. bar...

The Tag

Purpose

The tag provides information about what references or whatis referenced by an HTML document, in terms of information that is notusually included in the document. The tag is treated veryloosely in these cases and there can be several possible attributes forthis tag. The major purpose for the LINK element in Microsoft InternetExplorer 3.0 is for style sheet purposes and possibly for Visual BasicScript. Use of the tag with style sheets is covered in theStyle Sheets section (see Chapter 2, "Review of HTML"). The tag does not have a closing tag.

Syntax

Attributes

AttributeRequiredPurpose

RELSpecifies a relationship to the document, for instance the value, Made,would relate to the person who made the document.

REVSpecifies a reverse relationship, something that references the document the link tag is in. This is not commonly used.

TITLESpecifies a title of the item the link references or is referencedby.

HREFSpecifies a URL for the referenced or referencing item.

TYPESpecifies what MIME type the referencing or referenced item is. Inthe case of style sheets, this would be, style/css.

Example

The Tag

Purpose

The tag allows meta-information to exist in the document.Special information that further describes the document can be includedas well.

Syntax

Attributes

AttributeRequiredPurpose

HTTP-EQUIVSpecifies what function or task to perform on the document. InternetExplorer has only one value for this: "refresh".

TYPESpecifies what the purpose of the meta information.

CONTENTSpecifies the CONTENT of HTTP-EQUIV, or TYPE.

The value, "refresh", for the HTTP-EQUIV attribute impliesthat the document should be refreshed after the amount of time specifiedby the VALUE attribute. Additionally, the VALUE attribute can specify anotherURL to load after a given time in the form of:

VALUE = "n URL"

where, n is the number of seconds to load the document and URL is thelocation of the document to load.

Example

The Tag

Purpose

The tag specifies the title of the document it is in.The value that is encapsulated in the title tag is displayed in the titlebar of Internet Explorer.

Syntax

...

Attributes

None.

Example

This is an HTML document

Body Tags

The Tag

Purpose

The , or anchor tag, specifies a hyperlink, which is used foraccessing other documents and resources. Whatever is encapsulated by theanchor tag is either an anchor, which is accessed by other resources, ora link, which accesses other anchors and resources.

Syntax

...

Attributes

AttributeRequiredPurpose

HREFSpecifies the resource to hyperlink to, this can be in the form ora URL or a filename.

NAMEIdentifies the anchor or hyperlink

TARGETSpecifies the window or frame in which the resource is loaded.

Example

Go To MallufConsulting

[ccc] Services Homepage

The Tag

Purpose

The tag renders the text it surrounds in italicsto represent an e-mail, postal, or other contact address.

Syntax

...

Attributes

None.

Example

123 Main Street

Anytown, USA

87743-0123

The TagPurposeThe tag renders the text it encapsulates in bold.Syntax...AttributesNone.ExampleThe text at the end of this line is in bold.The TagPurposeThe tag increases the size of the text it encapsulates.The size of this text is slightly larger than normal paragraph text.Syntax...AttributesNone.ExampleWe want you to notice this text.The TagPurposeThe tag is used in citing references, or other material.The text that is surrounded by the tags is indented.5 inches to the right.Syntax...AttributesExampleThis sentence of words is indented - can't yousee???The TagPurposeThe tag specifies the beginning and the end of the Contentportion of the document, or of the document that is actually displayed.Syntax...AttributesAttributeRequiredPurposeBACKGROUNDSpecifies an image that is tiled across the back of the screen.BGCOLORSpecifies a background color. This color can be in the form of oneof several colors names, or a hexadecimal value in the form of #rrggbbwhere rr is the hexadecimal value for red on the 0-255 color palette, ggand bb are the hexadecimal value for green and blue on the 0-255 colorpalette, respectively. The 16 standard colors and their hexadecimal equivalentSare listed in the table at the end of the section. Refer to the last sectionof this appendix for a full list of supported color names.BGPROPERTIESSpecifies the properties of the BACKGROUND attribute. The only validvalue for BGPROPERTIES now, is fixed, which indicates that the graphicspecified by BACKGROUND will not be tiled but rendered as a watermark.LEFTMARGINSpecifies the width of the left margin of the page (values are in pixels).LINKSpecifies the color of an unvisited link in the same manner as BGCOLOR.TEXTSpecifies the color of the foreground text in the same manner as BGCOLOR.TOPMARGINSpecifies the width of the top margin of the page (values are in pixels).VLINKSpecifies the color of visited links in the same manner as BGCOLOR.Color NameHexadecimal Equivalent"Aqua""#00FFFF""Black""#FFFFFF""Blue""#0000FF""Fuchsia""#FF00FF""Gray""#808080""Green""#008000""Lime""#00FF00""Maroon""#800000""Navy""#000080""Olive""#808000""Purple""#800080""Red""#FF0000""Silver""#C0C0C0""Teal""#808000""White""#FFFFFF""Yellow""#FFFF00"ExampleThisThis
And this are in the bodyThe
TagPurposeThe
tag inserts line breaks in HTML. Normally, there areno line breaks in HTML; text continues to flow until it reaches the endof the browser, then a line break occurs.Syntax
AttributesAttributeRequiredPurposeCLEARCauses all the text following the
to be aligned with themargin specified by the CLEAR attribute. For instance, if there were aleft aligned image tag, and a
tag following some text had theattribute: CLEAR="left", then the text would be left alignedwith the left-hand margin right below the image. The "right"value does the for the right side. The "all" value causes thetext following the
tag to be placed past all floating images.ExampleThis line has no breaks in itThis
line does
have brea
ks.
Some textis here
and some text is just below theimage, on the left side.The TagPurposeThe tag centers any text, pictures, or other entitiesit surrounds.Syntax...AttributesNone.ExampleThis text is left aligned.This text is centeredThe TagPurposeThe tag renders text in italics and also has thesame purpose as the tag: to cite references, or othermaterial.Syntax...AttributesNone.Example"He didn't do it" the reportersaid.Client-Side Image MapsThis section covers client-side image maps and how to implement them.Currently, Microsoft Internet Explorer and Netscape Navigator support client-sideimage maps. The USEMAP attribute of the image tag accesses client sideimage maps. The USEMAP attribute indicates which map it should bind to(or in essence, which map it should use). The map contains coordinate-definedareas (polygons, circles, rectangles), which outline hotspots. When theuser clicks a hotspot in the image, the coordinates are compared to thearea regions specified by the map and the appropriate action specifiedby the HREF attribute is made.Syntax...AttributesAttributeRequiredPurposeNAMEGives the map a name, which is referenced by the USEMAP attribute ofthe tag.The TagThe tag is used to specify the various hotspots on an image.The tag is encapsulated inside the tag and isthe only tag allowed in the tag. The table below lists theattributes of the tag.AttributeRequiredPurposeCOORDSSpecifies the coordinates of a hotspot area specified by the SHAPEattribute. The coordinates are specified in (x,y) pairs until the coordinatescover an area. For example, a polygon would have the value: COORDS="x1,y1,x2,y2,..."and so on.HREFIndicates where the user will go (in the form of a URL) if they clickin a region that is specified by the corresponding COORDS attribute.NOHREFIndicates that if the user clicks in a region specified by the correspondingCOORD tag, then no action will occur. This attribute is required if theHREF attribute is not used.SHAPESpecifies the shape of the hotspot region. The valid values are: circle,rectangle, and polygon. With a circle you must specify the center pointof the circle (x,y), then the radius of the circle, in that order. (COORDS="center.x,center.y,radius")With a rectangle, you must specify the coordinates of two adjacent endpointsof the rectangle (COORDS="x1,y1,adjacent.x2,adjacent.y2"). With a polygon, you specify multiple sets of (x,y) coordinates thatdo not overlap (COORDS="x1,y1,x2,y2,x3,y3,...").The values "polygon", "circle," and "rectangle"can be shortened to "poly", "circ", and "rect",respectively, for the SHAPE attribute of the AREA tag.ExampleSee Listing B.3 in the Frames section for an example.The TagPurposeThe tag renders its encapsulated text in a fixed-widthfont, similar to that of a code listing.Syntax...AttributesNone.ExampleThe code for a simple C program#include
main()
{
printf("This is a test");
}
The TagPurposeThe tag is one of the many tags that renders text in italics.Syntax...AttributesNone.ExampleThis is an example of the tag.The TagPurposeThe tag, is used to emphasize a particular group of wordsit surrounds. The text it surrounds is in italics. The only differencebetween the tag and other italic rendering tags is that is used in a logical sense.Syntax...AttributesNone.ExampleYou must turn on the computer to get anythingdone.The TagPurposeThe tag is used for changing the size, color, and faceof the text it surrounds.Syntax...AttributesAttributeRequiredPurposeCOLORSpecifies the new color of the text. The color is specified by oneof several color names (noted in the tag section) or by ahexadecimal value, in the form of #RRGGBB (where RR, GG, and BB is a hexadecimalnumber from 0 to FF (255) in red, green and blue respectively.FACESpecifies the new font for the text being encapsulated. Whether thefont is shown or not, depends on whether it is available on the user'ssystem. Some common fonts are listed in the following table. Also, youcan specify multiple font names in case the user does not have the firstspecified font (in other words, if FACE="Times, Arial, Bahamas",the Times font will be used, if it's not available, the Arial font willbe used and so on.) There is technically no limit to the number of alternatefonts one can specify.SIZESpecifies the size of the text surrounded. This can be a size relativeto the base size (1 by default) or a new size (from 17). A relative sizeto the default size (3), or to the default size specified by ,can also be used (such as, SIZE="+2" means two sizes larger thanthe default size or "5" and SIZE="-1" is one size smallerthan the default size of "2".)Common Font NamesArialCourierCourier NewComic Sans MsDingbatsExpoFrankfurtGothicScriptTimes New RomanWingdingsThe listed fonts only work on a user's system if they are available(if the font is installed). The listed fonts are fonts that are most likelyto be on a user's Windows operating system.ExampleThe following text is the largest size:
The Largest Size
The following text is one size bigger that the current text
One Size Bigger
This text is one size larger than the normal text,blue and is rendered in the Arial FONT FormsThis section is devoted to forms and how to implement them. Forms arean important tool for Visual Basic Script and they can provide more interactiveWeb pages. The syntax expressed in the next section is the syntax for formsin general and all the form controls or elements are encapsulated insidethe form.Form Syntax...Form AttributesThe following are attributes that forms use to specify how and whereto send its data:AttributePurposeACTIONSpecifies the URL of where the data should be submitted when the usersubmits the form. The URL is usually a CGI (common gateway interface) program,which processes the data.METHODSpecifies how the data should be submitted. There are two valid valuesfor METHOD. These include: "get", and "post". The GetMETHOD should be used when most of the data the user submits is not goingto be permanently stored (as in a search). The Post METHOD is used whenall the data the user submits is intended to be kept (as in a guestbook).Also, when the Get METHOD is used, all the data in the form is appendedto the URL. When the Post METHOD is used, all the data is sent via a setof variables and arrays, called the HTTP post transaction.When using just Visual Basic Script with forms (the form is not goingto be further processed), the previous attributes are unneeded. InternetExplorer 3.0 also allows for form controls ( and tags) to be used without specifying a parent form.Form ControlsThere are two actual tags for specifying all the form controls. Thesetags are the tag, and the tag. The tag specifies most of the form's controls, while the tagis used for providing list boxes and drop-down lists.The TagThe tag is a single tag used for specifying various formcontrols including the: button, text, radio, and checkbox controls. Thetable in this section specifies all the attributes of the tag and the controls you can specify.SyntaxAttributesAttributeRequiredPurposeALIGNSpecifies the alignment of the image (used with the image control).Valid values are middle, bottom, and top.CHECKEDIndicates whether a checkbox or a radio button is selected or checked(used with radio buttons and checkboxes). CHECKED is a valueless attributeand its presence inside the checkbox, or radio input tag indicates thatthe button is selected.MAXLENGTHSpecifies the maximum amount of characters that can be entered intoa text control.NAMEIdentifies the form control.SIZESpecifies the size of the control (text box or text area). For a textbox, the width in characters is given SIZE="width". For a text-area,the width and the height are specified with the characters, SIZE="width,height".SRCUsed with the image control to specify the location of the image (eitherby URL or filename).TYPESpecifies the type of form control. See the next table for the typesof form controls available and how to implement them.VALUEGives a default value for the form control. For buttons, this givesthe button a name.TYPE (control) ValueFunction"button"Makes a clickable button control that has no special function (seethe "submit" and "reset" values.)"checkbox"Indicates a square box that can be checked on and off. A group of checkboxeswith related data should be given the same name. The default submittedvalue, if none is specified, is "on." Values are submitted onlyif the checkboxes are checked."hidden"Indicates a hidden input control (the control is not seen by the userand is commonly used for values that the user does not need to see)."image"Specifies a clickable image in the form which submits the coordinatesof the user's click in the form of image-name.x and image-name.y. Image-nameis the name of the image assigned by the NAME attribute and the appended.x and .y values are the x and y coordinates respectively where the origin(where x and y both equal zero) is at the top left-hand corner of the image."password"Specifies a text box in which all the input is hidden by *'s."radio"Specifies a radio button that remains selected when clicked. If severalradio buttons are given the same name, only one of the collection remainsselected when clicked."reset"Specifies a button that resets the entire form when clicked."submit"Specifies a button that submits the form to the URL specified by theACTION attribute of the tag."text"Specifies a plain text box that can accept text characters and strings."textarea"Similar to a text box but it can span several lines and it enablesthe user to input multiple lines of text.The TagThe tag is used for specifying drop-down, or list boxcontrols. For items in these controls, the tag uses the tag to specify these items.Syntax...AttributesAttributePurposeMUTIPLESpecifies that multiple items can be selected from the drop-down orlist box.NAMEIdentifies the name of the drop-down or list box.SIZESpecifies how many entries of the tag should be displayed.As a rule of thumb, the SIZE determines whether the tagis a drop-down, or list box. If the SIZE="1" (by default it does)then the tag becomes a drop down box. If the value for SIZEis any other positive number, then the tag becomes a listbox displaying (vertically) the items in the box. If there are more itemsin the list box than those displayed, then the box becomes scrollable.The TagThe tag is what specifies the entries, or list itemsin the tag. The general syntax for the option tag is: .All the words that follow the option tag become the text that is displayedon screen. The following table specifies the attributes of the tag.AttributePurposeSELECTEDIs a valueless attribute. Its purpose is to set one of the optionsas selected (the item is highlighted). If no SELECT attribute exists inany of the option tags, then the first attribute is selected by default.VALUEGives a value to the option tag. This value is submitted with the formif the option is selected.ExampleThe code in Listing B.1 can also be referenced off the accompanyingCD.Listing B.1 FORMD1.HTMA Demonstration of all the Form ControlsSample FormCheckboxes
Small:
Medium:
Large:
Buttons

HiddenFields
ImageControls

PasswordBox

RadioButtons
Yes No Maybe