/* XMLHttprequest functions */

function load(url, target_div_id, args, callback){
	
	// cheating here to add session id to all ajax calls
	if (typeof(sessid) != 'undefined') {
   	url = url + sessid;
	}
	
	var req = 0;
	
	if(window.XMLHttpRequest) {
		req = new XMLHttpRequest();
	} else {
		req = new ActiveXObject("Microsoft.XMLHTTP");
	}

	req.onreadystatechange = function() { process_request(req, target_div_id, callback); };
	req.open("POST", url, true);
	req.setRequestHeader("Content-Type","application/x-www-form-urlencoded; charset=UTF-8");
	req.send(args);
	
	
}

function process_request(req, target_div_id, callback){
	// only if req shows "complete"
	
	if (req.readyState == 4) {
		if (req.status == 200) {
			if(target_div_id){		
				//alert(req.responseText);
				var target_div = document.getElementById(target_div_id);
				target_div.innerHTML = req.responseText;
				if(callback){
					callback();
				}
			}
		} else {
			alert("(error) target_div_id = " + target_div_id);
		}
	}
}