var req;

function image_swap(item, new_image) {
	item.src = "/images/" + new_image;
}

function loadData(data_url, data_param_name, data_param, data_element_id) {
	url = data_url + "?" + data_param_name + "=" + data_param;
	
	if (window.XMLHttpRequest) {
		req = new XMLHttpRequest();
	} else if(window.ActiveXObject) {
		req = new ActiveXObject("Microsoft.XMLHTTP");
	} else {
		return;
	}
	
	req.onreadystatechange = Function("loadDataReadyStateChange('" + data_element_id + "', true)");
	req.open("GET", url, true);
	req.send("");
}

function loadDataReadyStateChange(data_element_id, show_loading) {
		
	dataNode = document.getElementById(data_element_id);
	
	switch (req.readyState) {
		case 0:
			break;	
		case 1:
			if (show_loading == true) {
				dataNode.innerHTML = "<img src=\"/images/spinner.gif\"> loading...";
			}
			break;
		case 2:
			if (show_loading == true) {
				dataNode.innerHTML = "loaded";
			}
			break;
		case 3:
			break;
		case 4:
			if (req.status == 200) { // only if "OK"
				dataNode.innerHTML = req.responseText;
			} else {
				dataNode.innerHTML = "error loading data...please try again";
			}
	}
}