Use Ajax technology to complete the home page login function through the XMLHttpRequest object

<script type="text/javascript">

//创建XMLHttpRequest对象

function createXMLHttpRequest(){

if(window.XMLHttpRequest){
return xmlhttprequest=new XMLHttpRequest();
}else{
return xmlhttprequest=new ActiveXObject("Microsoft.XMLHTTP");
}

}

//登录按钮执行的方法

function doStart(){

var logname=document.getElementById("loginName").value;
var logpass=document.getElementById("loginPsw").value;

var userinfo="inAccount="+logname+"&inPsw="+logpass;

var url="users/users_pswCheck.action";

xmlhttprequest=createXMLHttpRequest();

xmlhttprequest.onreadystatechange=getresultValue;

xmlhttprequest.open("post",url,true);
xmlhttprequest.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
xmlhttprequest.send(userinfo);

}

//回调方法

function getresultValue(){
if(xmlhttprequest.readyState==4 && xmlhttprequest.status==200){

var result=xmlhttprequest.responseText;

if(result=="success"){
window.location.href="index.jsp" rel="external nofollow" ;
} else {

document.getElementById("xiaoxi").innerHTML="登录失败！";

}

}

}

//页面的按键事件，即当按的是回车键时触发该事件

function keybutton(){

if(event.keyCode==13){ 
doStart(); 
return;
} 
}
</script>