客户端代码：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
</head>
<script language="javascript">
var xmlHttp;
function createXMLHttpRequest(){
if(window.ActiveXObject){
xmlHttp = new ActiveXObject("microsoft.XMLHTTP");
}
else if(window.XMLHttpRequest){
xmlHttp = new XMLHttpRequest();
}
}
function sendRequest(){
createXMLHttpRequest();
var name = document.getElementById("name").value;
url = "String_check.php?page="+name;
xmlHttp.onreadystatechange = callback;
xmlHttp.open('GET',url,true);
xmlHttp.send(null);
}
function callback(){
if(xmlHttp.readyState == 4){
if(xmlHttp.status == 200){
document.getElementById("show").innerHTML = "您输入的字符串为："+ xmlHttp.responseText;
}
}
}
</script>
<body>
<p>AJAX test;</p>
<p><br/>
<input type="text" id="name" onkeyup="sendRequest();" />
<br/>
<span id="show"></span>
</p>
</body>
</html>
服务器端代码：
<?php
header('Content-type: text/html;charset=GB2312');
$ename = $_GET["page"];
if ($ename == "") {
$ename = "请输入：";
}
echo ($ename);
exit(0);
?>