/*
 * this function returns a XMLHttpRequest
 */
function getXMLHttpRequest() {
	if (navigator.appName == "Microsoft Internet Explorer") {
		req = new ActiveXObject("Microsoft.XMLHTTP");
	} 
	else {
		req = new XMLHttpRequest();
	}
	return req;
}

/*
 * gets announcement's page links from a.href
 */
function getContent(page, div_id) {
	var request = getXMLHttpRequest();
	if (request) {
		displayLoading(document.getElementById(div_id)); // element is NULL mesajı veiryor.
		request.open("get", page);
		request.onreadystatechange = function() { render_to_response(request, div_id); };
		request.send(null);
	}
}

/**
 * 'page' sayfasını 'parameters' parametreleriyle çağırır ve sonucu 'div_id' 
 * id'li kısma ekler.
 */
function getContentParams(page, parameters, div_id) {
	var request = getXMLHttpRequest();
	if (request) {
		displayLoading(document.getElementById(div_id));
		request.open("GET", page+'?'+parameters, true);
		request.onreadystatechange = function() { render_to_response(request, div_id); }
		request.send(null);
	}
}

/*
 * this function render in a div id
 * with requested page's content
 */
function render_to_response(request, div_id) {
	if (request.readyState == 4) {
		var response = request.responseText;
		if (response && response!= "") {
			document.getElementById(div_id).innerHTML = response;
		}
	}
} 

function displayLoading(element) {
	  while (element.hasChildNodes()) {
	    element.removeChild(element.lastChild);
	  }
	  var image = document.createElement("img");
	  image.setAttribute("src","face/media/images/loading.gif");
	  image.setAttribute("alt","Loading...");
	  element.appendChild(image);
	}