<script type="text/javascript" src="jquery-1.3.2.js"></script>

<script type="text/javascript">

$(function() {

$("#loading_img").click(

function()

{

$.ajax({

type:"GET",

url:"demo.php",

data:"name=wuxiaoyong",

beforeSend:loading,//执行ajax前执行loading函数.直到success

success:Response //成功时执行Response函数

})

}

)

});

function loading(){

$('#loading_img').html('<img src="data:images/loading.gif"/>');

}

function Response(data){

$('#loading_img').html(data);

}

</script> 

<div id="loading_img">点击加载</div>