Prototype入门_ajax收藏-优快云博客

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>

<script type="text/javascript">
var xmlRequest = null;
var READY_STATE_UNLOAD = 0;
var READY_STATE_LOADING = 1;
var READY_STATE_LOADED = 2;
var READY_STATE_INTERACTIVE = 3;
var READY_STATE_COMPLATE = 4;

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

function check() {
var params = "usr=";

sendRequest("upload2.do", params, "get");

return false;
}

function sendRequest(url, params, method) {
if (!method){ method="post"; }

xmlRequest = getXMLHttpRequest();
if (xmlRequest) {
xmlRequest.onreadystatechange=callBack;

xmlRequest.open(method, url, true);
xmlRequest.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xmlRequest.send(params);
}

}

function callBack() {
var ready = xmlRequest.readyState;
var data = null;

if (ready == READY_STATE_COMPLATE) {
data = xmlRequest.responseXML;

var flag = data.getElementsByTagName("flag")[0].firstChild.nodeValue;

if (flag == "false") {
alert('user or password error,');
} else {
window.open("ok", "_top");
}
}
}

</script>

</head>
<body>

<a href="javascript:check();">kkkkkkkkk</a>
</body>
</html>