Browser Detection for ASP.Net Ajax

Here's a class that I found in client-side Microsoft AJAX library for browser detection.  It's Sys.Browser.Agent.  For a while, it wasn't documenated anywhere in the Microsoft on-line documentation, but it must have just appeared recently at:

One example of how this class can be used:

if (Sys.Browser.agent == Sys.Browser.InternetExplorer) 
    { 
    alert("Display this message for IE visitors");
    } 

For Sys.Browser.agent, the four values it can return are:

• Sys.Browser.InternetExplorer
• Sys.Browser.Firefox
• Sys.Browser.Safari
• Sys.Browser.Opera