function CheckBrowser() {

  if (document.cookie.indexOf('browserChecked=true') != -1)
	return;  //browser already checked

  document.cookie = "browserChecked=true"; //set cookie so that browser is only checked once

  var ua, s, i;

  var isValid = false; 
  var version = "";

  ua = navigator.userAgent;

  s = "MSIE";
  if ((i = ua.indexOf(s))) 
  {
    version = parseFloat(ua.substr(i + s.length));
    if (version < 6)
    {
	var msg = "This site was designed for use with Microsoft Internet Explorer 6.0 or higher.\n"
	+  	  "If you continue to use your current browser, certain functionality within the\n"
	+  	  "site may not work properly."
	alert(msg);
    }    

  }
}
CheckBrowser();