一般ajax写法
function test(url, username, password, jQuery,callback) { url = url || "/test.jsp"; jQuery.ajax({type:Get, url: url, async: true, password:password, username:username, complete:function(xmlhttp, status){ var ok = (200 <= xmlhttp.status && xmlhttp.status < 300) || xmlhttp.status == 1223; // status 204 -> 1223 in IE if (ok) { callback(true); } else { callback(false); } }}); var xmlhttp; if (window.XMLHttpRequest) { xmlhttp = new XMLHttpRequest() } else { xmlhttp = new ActiveXObject("MSXML2.XMLHTTP"); } xmlhttp.onreadystatechange = function() { if (xmlhttp.readyState == 4) { var ok = (200 <= xmlhttp.status && xmlhttp.status < 300) || xmlhttp.status == 1223; // status 204 -> 1223 in IE if (ok) { callback(true); } else { callback(false); } } }; xmlhttp.open("Get", url, true, username, password); try { xmlhttp.send(null);//error } catch (e) { callback(null); }}