Jquery internet explorer browser compatibility issue

function runBrowserCheck()
{
  var bIE = false;
  var iBrowserType = -1;
  var iBogusBrowserVariant = 0;
 
  var cUserAgent = window.navigator.userAgent;
  var cAppName = window.navigator.appName;
 
  bIE = (cUserAgent.indexOf("msie") >= 0);
 
  if (bIE)
  {
    //IE8
    if (cUserAgent.indexOf("MSIE 8.0") >= 1)
        iBrowserType = 5;
    if (cUserAgent.indexOf("MSIE 9.0") >= 1)
        iBrowserType = 5;
  }
}

I am using this jquery to check browser compatibility,but it Shows Internet explorer browser incompatibility issue.