Ajax用户名检测

2008/12/19

checkUsername.php

<?php
$info= "http://".$_SERVER["HTTP_HOST"].$_SERVER["REQUEST_URI"];
parse_str($info);
if($username == "wxxslt"){
echo "failure";
}
else{
echo "success";
}
?>

check.html

<!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>检测用户名</title>
<script language="javascript" type="text/javascript">
  function createRequest(){
    var xmlHttp = false;
    if (window.XMLHttpRequest) { // 在非IE浏览器中创建XMLHttpRequest对象
      xmlHttp = new XMLHttpRequest();
    } else if (window.ActiveXObject) { //通过ActiveX创建XMLHttpRequest
    try {
      // 尝试按新版InternetExplorer方法创建
      xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (error1) { // 创建请求的ActiveX对象失败
      try {
        // 尝试按老版InternetExplorer方法创建
        xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
      } catch (error2) {
        // 不能通过ActiveX创建XMLHttpRequest
        xmlHttp = false;
      }
    }
  }
  return xmlHttp;
  }
  function checkUsername(username){
    var checkRet = document.getElementById("checkRet");
    var form=document.forms[0];
    var name=form.username;
    if(name.value!=""){
  checkRet.innerHTML = "请稍候，正在检测用户名...";
    }
    var xmlHttp = createRequest();
  var url = "checkUsername.php?username=" + username;
  xmlHttp.open("get",url);
  xmlHttp.onreadystatechange = function(){
      if(xmlHttp.readyState==4){
        if(xmlHttp.status==200){
         if(xmlHttp.responseText=="success"&&name.value!=""){
            checkRet.innerHTML = "恭喜你，该用户名还没有被使用!";
         }else if(xmlHttp.responseText=="failure"){
           checkRet.innerHTML = "对不起，该用户名已经被占用！";
           name.value="";
           name.focus();
        }
      }
     }
    }
    xmlHttp.send(null);
  }
</script>
</head>
<body>
<form id="form1" name="form1" method="post" action="">
  <label>用户名：
  <input type="text" name="username" onblur="checkUsername(this.value)" /><div id="checkRet"></div>
  </label>
  <br/>
  <label>性别：
  <input type="text" name="sex" />
  </label>
</form>
</body>
</html>