php 文件 1
<html>
<head>
<title> 在 PHP 中应用 AJAX 技术检测用户名 </title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<style type="text/css">
<!--
body {
margin-bottom: 0px;
background-color: #64284A;
}
td{font-size:12px;}
# style5 {
font-family: "文鼎淹水体";
font-size: 18pt;
color: #64284A;
}
# style2 {font-size: 16px; font-family: "文鼎霹雳体"; color: #64284A;}
# style3 {font-family: "文鼎圆立体"}
# style4 {font-family: "文鼎淹水体"}
-->
</style>
</head>
<body>
<script language="javascript">
var http_request = false;
function createRequest(url) {
// 初始化对象并发出 XMLHttpRequest 请求
http_request = false;
if (window.XMLHttpRequest) { //Mozilla 等其他浏览器
http_request = new XMLHttpRequest();
if (http_request.overrideMimeType) {http_request.overrideMimeType("text/xml");
}
} else if (window.ActiveXObject) { //IE 浏览器
try {http_request = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try {http_request = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e) {}}
}
if (!http_request) {alert("不能创建 XMLHTTP 实例!");
return false;
}
http_request.onreadystatechange = alertContents; // 指定响应方法
http_request.open("GET", url, true); // 发出 HTTP 请求
http_request.send(null);
}
function alertContents() { // 处理服务器返回的信息
if (http_request.readyState == 4) {if (http_request.status == 200) {alert(http_request.responseText);
} else {alert('您请求的页面发现错误');
}
}
}
</script>
<script language="javascript">
function checkName() {
var username = form1.username.value;
if(username=="") {window.alert("请填写用户名!");
form1.username.focus();
return false;
}
else {createRequest('checkname.php?username='+username+'&nocache='+new Date().getTime());
}
}
</script>
<form name="form1" method="post" action="">
<table width="1003" height="628" border="0" align="center" cellpadding="0" cellspacing="0">
<tr>
<td valign="top" background="images/bg.JPG"><table width="1003" border="0" cellspacing="0" cellpadding="0">
<tr>
<td width="242" height="346"> </td>
<td width="532" height="30" align="center" valign="bottom" class="style5"><span class="style2"> 用户注册 <span class="style3"> <span class="style4"></span></span></span></td>
<td width="229"> </td>
</tr>
<tr>
<td> </td>
<td align="center"><table width="92%" border="0" cellpadding="0" cellspacing="0">
<tr>
<td width="29%" height="30" align="center"> 用 户 名：</td>
<td width="71%" height="24"><input name="username" type="text" id="username" size="20">
<a href="#" onClick="checkName();">[检测用户名]</a> </td>
</tr>
<tr>
<td height="24" align="center"> 真实姓名：</td>
<td height="24"><input name="truename" type="text" id="truename" size="20">
*</td>
</tr>
<tr>
<td height="24" align="center"> 密 码：</td>
<td height="24"><input name="pwd1" type="password" id="pwd1" size="20">
*</td>
</tr>
<tr>
<td height="24" align="center"> 确认密码：</td>
<td height="24"><input name="pwd2" type="password" id="pwd2" size="20">
* </td>
</tr>
<tr>
<td height="24" align="center"> 性 别：</td>
<td height="24"><input name="sex" type="radio" value="男" checked>
男
<input type="radio" name="sex" value="女">
女 </td>
</tr>
<tr>
<td height="24" align="center" style="padding-left:10px">Email：</td>
<td height="24" class="word_grey"><input name="email" type="text" id="email" size="28">
*</td>
</tr>
<tr>
<td height="24" align="center"> 个人主页：</td>
<td height="24" class="word_grey"><input name="homepage" type="text" id="homepage" size="28"></td>
</tr>
<tr>
<td height="40" colspan="2">
<input name="imageField" type="image" src="images/submit.gif" width="64" height="20" border="0">
<input name="imageField2" type="image" src="images/reset.gif" width="64" height="20" border="0"></td>
</tr>
</table></td>
<td> </td>
</tr>
</table></td>
</tr>
</table>
</form>
</body>
</html>php 文件 2
<?php require 'conn.php'; //Ajax 中先用 encodeURIComponent 对要提交的中文进行编码 @$username=$_GET[username]; $sql=$conn->query("select * from youer where username='".$username."'"); $info=mysqli_fetch_array($sql); if ($info){ echo" 很报歉! 用户名[".$username."] 已经被注册!"; }else{ echo" 祝贺您! 用户名 [".$username."] 没有被注册!"; }
?>
正文完
