var xmlHttp
function chonquan(str,w){ 	
	xmlHttp=GetXmlHttpObject();
	if (xmlHttp==null){
		alert ("Your browser does not support AJAX!");
		return;
	} 
	if (str.length > 0){				
		var url="includes/chonquan.php";
		var post_data = "q=" + str + "&w=" + w;
		xmlHttp.onreadystatechange=trangthaichon;
		xmlHttp.open("POST", url , true);
		xmlHttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");		
		xmlHttp.send(post_data);
	} 
	else{
		document.getElementById("txtchonquan").innerHTML = " ";
	} 
}

function trangthaichon(){ 
	if (xmlHttp.readyState==4){ 
		document.getElementById("txtchonquan").innerHTML=xmlHttp.responseText 		
	} 
}

function GetXmlHttpObject(){
	var xmlHttp=null;
	try{
	  // Firefox, Opera 8.0+, Safari
	  xmlHttp=new XMLHttpRequest();
	  }
	catch (e){
	  // Internet Explorer
		try{
	    	xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
    	}
		catch (e){
		    xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
	    }
  	}
	return xmlHttp;
}