var xmlHttp=null;

function setXmlHttp()
{
	try
	  {// Firefox, Opera 8.0+, Safari, IE7
	  xmlHttp=new XMLHttpRequest();
	  }
	catch(e)
	  {// Old IE
	  try
	    {
	    xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
	    }
	  catch(e)
	    {
	    alert ("Your browser does not support XMLHTTP!");
	    return false;  
	    }
	  }

}