JQ 调用后台方法即Ajax方法基础知识

<link href="@Scripts/My97/skin/default/datepicker.css" rel="stylesheet" type="text/css" />
<script src="@Scripts/My97/WdatePicker.js" type="text/javascript"></script>
<link href="@Scripts/My97/skin/WdatePicker.css" rel="stylesheet" type="text/css" />

<!--验证引入-->
<link href="@Css/form.css" rel="stylesheet" type="text/css" />
<script src="@Scripts/jquery-1.4.4.min.js" type="text/javascript"></script>
<script src="@Scripts/jquery.validate.min.js" type="text/javascript"></script>
<script src="@Scripts/messages_cn.js" type="text/javascript"></script>
<script src="@Scripts/jquery.pstrength-min.1.2.js" type="text/javascript"></script>
<script src="@Scripts/commvalidate.js" type="text/javascript"></script>
<script src="@Scripts/js_comm.js" type="text/javascript"></script>

<!--验证引入结束-->
<style type="text/css">
.style1
{
width: 327px;
}
</style>
<script language="javascript" type="text/javascript">
$(function() {
$("#btnCheck").click(function() {
$.ajax({
type: "Post",
url: "BuyerReg.aspx/CheckUserName",
//方法传参的写法一定要对，str为形参的名字,str2为第二个形参的名字
data: "{'username':'" + $("#txtUserName").attr("value") + "'}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function(data) {
//返回的数据用data.d获取内容
alert(data.d);
},
error: function(err) {
alert(err);
}
});
//禁用按钮的提交
return false;
});
});
</script>

<link href="@Css/css.css" rel="stylesheet" type="text/css" />
</head>