var xmlhttp = null;
function getXmlHttp()
{
	if (window.XMLHttpRequest) return new XMLHttpRequest();
	if (window.ActiveXObject) return new ActiveXObject("Microsoft.XMLHTTP");
	return null;
}

function submitAjaxRequest(reqType, page, callBackFunction, postData)
{
	xmlhttp = getXmlHttp();
	if (xmlhttp != null)
	{
		xmlhttp.onreadystatechange=function(){
			if (xmlhttp != null){
				// alert (xmlhttp.readyState + ' ' + xmlhttp.status);
				if ((xmlhttp.readyState == 4) && (xmlhttp.status == 200)){
					callBackFunction(xmlhttp.responseText);
					xmlhttp=null;
				}
			}
		}
		xmlhttp.open(reqType, page, true);
		xmlhttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8');
		xmlhttp.send(postData);
	}
}

function submitAjaxGetRequest(page, callBackFunction)
{
	submitAjaxRequest('GET', page, callBackFunction, null);
}

function submitAjaxPostRequest(page, callBackFunction, postData)
{
	submitAjaxRequest('POST', page, callBackFunction, postData);
}