function ajaxPost(url, params, call_back) {
	ajaxRequest('POST', url, params, call_back);
}

function ajaxGet(url, call_back) {
	ajaxRequest('GET', url, null, call_back);
}

function ajaxRequest(type, url, params, call_back) {
	var xmlhttp = false;
	if (window.XMLHttpRequest) {
		xmlhttp = new XMLHttpRequest();
	} else {
		try {
			xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
		} catch(e) {
			try {
				xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (ex) {
				xmlhttp = false;
			}
		}
	}
	
	if (call_back == null || call_back == undefined) {
		call_back = function (response) { };
	}
	
	xmlhttp.open(type, url, true);
	xmlhttp.onreadystatechange = function() {
		if (xmlhttp.readyState == 4) {
			call_back(xmlhttp.responseText);
		}
	};
	xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	xmlhttp.send(params);	
}