//ajax方法封装
var req;
function getRequest() {	
	req = getXMLHttpRequestFromIE();	
	if (req == null) {
		req = new XMLHttpRequest();
	}	
}
function getXMLHttpRequestFromIE() {
	var namePrefixes = [ "Msxml3", "Msxml2", "Msxml", "Microsoft" ];
	for ( var i = 0; i < namePrefixes.length; i++) {
		try {
			var name = namePrefixes[i] + ".XMLHTTP";
			return new ActiveXObject(name);
		} catch (e) {
		}
	}
	return null;
}
function sendPostRequest(url,param,processFunc){	
    getRequest();   
    if (req) {
        req.onreadystatechange = processFunc;
        req.open("post", url, true);
        req.setRequestHeader("Content-Type","application/x-www-form-urlencoded;");
        req.send(param);
    }
}