ASP.NET

<br />
  function getInternetExplorerVersion()<br />
// Returns the version of Internet Explorer or a -1<br />
// (indicating the use of another browser).<br />
{<br />
  var rv = -1; // Return value assumes failure.<br />
  if (navigator.appName == 'Microsoft Internet Explorer')<br />
  {<br />
    var ua = navigator.userAgent;<br />
    var re  = new RegExp("MSIE ([0-9]{1,}[\.0-9]{0,})");<br />
    if (re.exec(ua) != null)<br />
      rv = parseFloat( RegExp.$1 );<br />
  }<br />
  return rv;<br />
}<br />