日期:2014-05-16 浏览次数:20852 次
学习HTML的几种触发
onblur 事件会在对象失去焦点时发生。onmouseup 事件会在鼠标按键被松开时发生。
最终要实现的效果是:



index.php代码如下:
<!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=utf-8" />
<title>无标题文档</title>
<script type="text/javascript" src="ajax.js"></script>
</head>
<body>
<form name="myform" action="" method="post">
用户名:
<input type="text" name="user" value="" onblur="funphp100()" />
<div id="php100"></div>
</form>
</body>
</html>// JavaScript Document
var xmlHttp;
function S_xmlhttprequest(){
if(window.XMLHttpRequest){
//Mozilla浏览器
xmlHttp=new XMLHttpRequest();
}else{
//IE浏览器
if(window.ActiveXObject){
try{
xmlHttp=new ActionXObject("Msxm12.XMLHTTP");
}catch(e){
try{
xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
}catch(e){
}
}
}
}
}
function funphp100(){
var f = document.myform.user.value;
S_xmlhttprequest();
xmlHttp.onreadystatechange = byphp;
xmlHttp.open("GET","for.php?id="+f,true);
xmlHttp.send(null);
}
function byphp(){
if(xmlHttp.readyState == 1){
document.getElementById('php100').innerHTML = "<img src = loading.gif>";
}
if(xmlHttp.readyState == 4){
if(xmlHttp.status == 200){
var byphp100 = xmlHttp.responseText;
document.getElementById('php100').innerHTML = byphp100;
}
}
}<?php
if($_GET[id]){
sleep(1);
$conn = mysql_connect('localhost','root','');
mysql_select_db('test',$conn);
$sql = "select * from `user` where `name` = '$_GET[id]'";
$q = mysql_query($sql);
if(is_array(mysql_fetch_row($q))){
echo "用户名已经存在";
}
else
echo "可以使用";
}
?>