var userName; var passWord; var xmlHttpRequest; //XmlHttpRequest对象 function createXmlHttpRequest(){ if(window.ActiveXObject){ //如果是IE浏览器 return new ActiveXObject("Microsoft.XMLHTTP"); }else if(window.XMLHttpRequest){ //非IE浏览器 return new XMLHttpRequest(); } } function onLogin(){ userName = document.f1.username.value; passWord = document.f1.password.value; var url = "LoginServlet?username="+userName+"&password="+passWord+""; //1.创建XMLHttpRequest组建 xmlHttpRequest = createXmlHttpRequest(); //2.设置回调函数 xmlHttpRequest.onreadystatechange = zswFun; //3.初始化XMLHttpRequest组建 xmlHttpRequest.open("POST",url,true); //4.发送请求 xmlHttpRequest.send(null); } //回调函数 function zswFun(){ if(xmlHttpRequest.readyState == 4 && xmlHttpRequest.status == 200){ var b = xmlHttpRequest.responseText; if(b == "true"){ alert("登录成功！"); }else{ alert("登录失败！"); } } }