织梦ajax跨域提交自定义表单和跨域验证码问题

<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>

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