function createREQ() { 
	try { 
		req = new XMLHttpRequest(); /* e.g. Firefox */ 
	} 
	catch(err1) { 
		try { 
			req = new ActiveXObject("Msxml2.XMLHTTP"); /* some versions IE */ 
		} 
		catch (err2) { 
			try { 
				req = new ActiveXObject("Microsoft.XMLHTTP"); /* some versions IE */ 
			} 
			catch (err3) { 
				req = false; 
			} 
		} 
	} 
return req; 
} 



function requestGET(url, query, req) {
	myRand=parseInt(Math.random()*99999999); 
	req.open("GET",url+'?'+query+'&rand='+myRand,true); 
	req.send(null); 
}


function requestPOST(url, query, req) {
	req.open("POST", url,true); 
	req.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded'); 
	req.send(query); 
}

function doCallback(callback,item) {
	eval(callback + '(item)'); 
}


function doCheck() {
	var cc = document.forms[0].customerno.value.length;
	if (cc <= 9) {
		document.forms[0].customerno.focus();
		return true;
	}
	else {
		doAjax('/ssgc/customer/viewbill/checktable.php','param='+document.forms[0].customerno.value,'cback','post','0');
	}
}


function doAjax(url,query,callback,reqtype,getxml) {
	// create the XMLHTTPRequest object instance
	cc = document.forms[0].customerno.value.length;
	if (cc > 0) { document.getElementById('aja').innerHTML = 'Verifying customer number...'; }
	document.forms[0].customerno.readOnly = true;
	document.forms[0].customerno.className = 'lock'
	var myreq = createREQ(); 
	myreq.onreadystatechange = function() { 
		if(myreq.readyState == 4) { 
			if(myreq.status == 200) { 
				var item = myreq.responseText; 
				if(getxml==1) { 
					item = myreq.responseXML; 
				} 
				doCallback(callback, item); 
			} 
		} 
	} 

if(reqtype=='post') { 
	requestPOST(url,query,myreq); 
} else { 
	requestGET(url,query,myreq); 
} 
}