织梦ajax跨域提交自定义表单和验证码问题

<script type="text/javascript" src="http://apps.bdimg.com/libs/jquery/1.6.4/jquery.min.js"></script>

<script>

function send(){

    $.ajax({

        cache:true,

        type:"POST",

        url:"http://www.b.com/plus/diy.php",

        data:$('#diyform').serialize(),

xhrFields:{withCredentials: true}, //ajax跨域提交需要

crossDomain:true, //ajax跨域提交需要

        success: function(data){

            if(data=="success"){

                alert('发送成功!');

            }else{

                alert('发送失败!');

            }

        }

    });

}

</script>

<form action="" enctype="multipart/form-data" method="post" id="diyform">

<input type="hidden" name="action" value="post" />

<input type="hidden" name="diyid" value="2" />

<input type="hidden" name="do" value="2" />

<input type="hidden" name="dede_fields" value="name,text" />

<input type="hidden" name="dede_fieldshash" value="c2be5bb5ec45d9d01ca9f60dc469b3fb" />

<p>

姓名：

<input type='text' name='name' id='name' />

</p>

<p>

验证码：

<input type="text" name="validate"><img src="http://www.b.com/include/vdimgck.php" align="absmiddle" onclick="this.src='http://www.b.com/include/vdimgck.php?tag='+Math.random();" style="cursor:pointer;">

</p>

<div onclick="send()">提交</div>

</form>

xhrFields:{withCredentials: true},

crossDomain:true,

header("Access-Control-Allow-Credentials:true");

header("Access-Control-Allow-Origin:http://www.a.com");