jQuery Ajax 简单的实现跨域请求

<script type="text/javascript" src="http://www.youxiaju.com/js/jquery-1.4.2.min.js"></script>
<script type="text/javascript">
$(function(){
$.ajax(
{
type:'get',
url : 'http://www.youxiaju.com/validate.php?loginuser=lee&loginpass=123456',
dataType : 'jsonp',
jsonp:"jsoncallback",
success  : function(data) {
alert("用户名："+ data.user +" 密码："+ data.pass);
},
error : function() {
alert('fail');
}
}
);
})
</script>

<?php
header('Content-Type:text/html;Charset=utf-8');
$arr = array(
"user" => $_GET['loginuser'],
"pass" => $_GET['loginpass'],
"name" => 'response'

);
echo $_GET['jsoncallback'] . "(".json_encode($arr).")";
?>