Differentiate IE7 browser and browser in IE7 compatibility mode

Question

Can I differentiate if client\'s browser is IE7 or e.g. IE9 in IE7 compatibility mode? I\'m trying to figure out if I can do a JS check on my site which would recognize two

Answer 1

Here is a fairly bullet-proof check that I did for a large-scale auction site based in San Jose.

var userAgentString = navigator.userAgent;

if(/MSIE 7\.0/gi.test(userAgentString) && /Trident/gi.test(userAgentString)){
    // compatibility mode
    // .... code goes here ....
}