dojo.isIE
<script src="../../js/dojo.js"></script>
defined in dojo/_base/_loader/hostenv_browser.js
Greater than zero if client is MSIE(PC). 0 otherwise. Corresponds to major detected IE version (6, 7, 8, etc.)
Examples
Example 1
if(dojo.isIE > 6){
// we are IE7
}