Detecting Browser Type and Capabilities

Web applications can appear in various types of browsers, but the capabilities of your application may be restricted in browsers VB .NET calls "downlevel." A downlevel browser is one that only supports HTML 3.2. Uplevel browsers, on the other hand, support:

ECMAScript (the formal name for JavaScript) version 1.2
HTML version 4.0
The Microsoft Document Object Model (MSDOM)
Cascading style sheets (CSS)

To determine the type and capabilities of the target browser, you can use the properties of the Request.Browser object in the Page_Load event. You can find these properties in Table 14.8; these properties hold either text or a Boolean value (for example, Request.Browser.Frames returns a value of True if the browser supports frames, while Request.Browser.Browser will hold the text "IE" if the browser is the Internet Explorer).

Table 14.8: *Request.Browser* properties.
To find this:	Use this:
Browser type (example: IE6)	Request.Browser.Type
Browser name (example: IE)	Request.Browser.Browser
Version (example: 6.0b)	Request.Browser.Version
Major version (example: 6)	Request.Browser.MajorVersion
Minor version (example: 0)	Request.Browser.MinorVersion
Platform (example: WinNT)	Request.Browser.Platform
Is a beta version?	Request.Browser.Beta
Is an AOL browser?	Request.Browser.AOL
Is Win16?	Request.Browser.Win16
Is Win32?	Request.Browser.Win32
Supports frames?	Request.Browser.Frames
Supports tables?	Request.Browser.Tables
Supports cookies?	Request.Browser.Cookies
Supports VB Script?	Request.Browser.VBScript
Supports JavaScript?	Request.Browser.JavaScript
Supports Java Applets?	Request.Browser.JavaApplets
Supports ActiveX Controls?	Request.Browser.ActiveXControls