function ajaxcagir(){
	 var retval=null;
     try
     {
          retval=new ActiveXObject("Msxml2.XMLHTTP");
     }
     catch(e)
     {
          try
          {
               retval=new ActiveXObject("Microsoft.XMLHTTP");
          } 
          catch(oc)
          {
               retval=null;
          }
     }

     if(!retval && typeof XMLHttpRequest != "undefined") 
     {
          retval=new XMLHttpRequest();
     }

     return retval;
}