Loading The Start Page

Like most applications we have a

default.htm

file in the application directory, which starts the application running by loading the main page. Because we're only supporting one browser (IE4/5) we need to check that the user has this browser to prevent the pages appearing to be broken when run on other incompatible browsers.

Checking the Browser Version

Here's the complete

default.htm

page. We use client-side code to detect the browser version and load the main wroxcars.asp
page into the full browser window if it's IE4 or better. If not, we display a message telling the user what happened:

<HTML>

<HEAD>

<TITLE>Loading, please wait..</TITLE>

<SCRIPT LANGUAGE="VBScript">

blnIE4 = False

strUA = navigator.userAgent

'use Microsoft's recommended browser type detection code:

intMSIE = Instr(strUA, "MSIE ") + 5

If intMSIE > 5 Then

If CInt(Mid(strUA, intMSIE, Instr(intMSIE, strUA, ".") _

- intMSIE)) >= 4 Then blnIE4 = True

End If

If blnIE4 Then top.window.location.href="wroxcars.asp"

</SCRIPT>

</HEAD>

<BODY>

<CENTER>

<H3>Sorry, this application requires Internet Explorer 4 or higher.</H3>

You can download the latest version of Internet Explorer from:<BR>

<A HREF="http://www.microsoft.com/ie/">http://www.microsoft.com/ie/</A>

</CENTER>

</BODY>

</HTML>

© 1998 by Wrox Press. All rights reserved.