//Initialize xmlhttp object

function GetXmlHttpObject(){

	var xmlHttp=null;

	//Use Firefox, Opera 8.0+, Safari

	try{

	  xmlHttp=new XMLHttpRequest();

  }

	catch(e){

  //Use Internet Explorer

  	try{

    	xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");

	  }

  	catch(e){

    	xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");

	  }

	}

	

	if (xmlHttp==null) {

  	alert ("Your web browser does not support XMLHTTP!");

	 	return null;

	}

	return xmlHttp;

}