function getInternetExplorerVersion()
// Returns the version of Internet Explorer or a -1
// (indicating the use of another browser).
{
  var rv = -1; // Return value assumes failure.
  if (navigator.appName == 'Microsoft Internet Explorer')
  {
    var ua = navigator.userAgent;
    var re  = new RegExp("MSIE ([0-9]{1,}[\.0-9]{0,})");
    if (re.exec(ua) != null)
      rv = parseFloat( RegExp.$1 );
  }
  return rv;
}
function checkVersion()
{
  var ver = getInternetExplorerVersion();
  if (ver > 0 && ver <= 6){
	msg = 'This site doesn\'t support your version ('+ver+') of Internet Explorer\n';
    msg += "You can upgrade it for free. Please visit:\n";
    msg += "http://www.microsoft.com/windows/internet-explorer/\n";
    msg += "\n";
    msg += "Alternatively you may like to try one of free alternatives\n";
    msg += "Google Chrome at http://www.google.com/chrome\n";
    msg += "FireFox at http://www.mozilla-europe.org/en/firefox/\n";
   	alert(msg);
  }
}

$(document).ready(function(){ 
	checkVersion();
});