function AJ()
{
   var obj;
   var browser = navigator.appName;
   browser =  browser.toLowerCase();

   if(window.XMLHttpRequest)
   {
      if(browser.indexOf("microsoft") != - 1)
      {
         obj = new ActiveXObject("Microsoft.XMLHTTP");
      }
      else
      {
         obj = new XMLHttpRequest();
      }
   }
   else if(window.ActiveXObject)
   {
      try
      {
         obj = new ActiveXObject('MSXML2.XMLHTTP.3.0');
      }
      catch(er)
      {
         try
         {
            obj = new ActiveXObject("Microsoft.XMLHTTP");
         }
         catch(er)
         {
            try
            {
               obj = new ActiveXObject("Msxml2.XMLHTTP");
            }
            catch(er)
            {

            }
         }
      }
   }
   return obj;
}

function isFile(str)
{
   var O = AJ();
   try
   {
      O.open("get", '' + str + '', false);
      O.send('');
      if(O.readyState == 4)
      {      	
         if(O.status == 200 || O.status == 0)
         {	
         		if(O.responseText.indexOf('error page') != -1){
         			return false;
         		}
            else{
          	  return true;
          }
         }
         else
         {
            return false;
         }
      }
   }
   catch(er)
   {
      return false;
   }
}