getJSON跨域SyntaxError问题分析

$(".check_mobile").click(function(){
var mobile = $('.mobile').val();
$.getJSON("http://www.test.com/user.php"+mobile+"&format=json&jsoncallback=", function(data){
if (data.succ == 1) {
var html = "<input type='hidden' name='cityid' value='"+data.data.cityid+"'><input type='hidden' name='communityid' value='"+data.data.communityid+"'>";
$(".r_m").append(html);
}
});
});

<"htmlcode">

header("Access-Control-Allow-Origin:http:www.test.com");
$b = json_encode($return);
echo "{$_GET['jsoncallback']}({$b})";
exit;



最后完整代码：


<"Access-Control-Allow-Origin:http:www.test.com");
if($_GET){
$mobile = $_GET['mobile'];
if ($mobile == '18831167979') {
$user = array(
'city' =>'石家庄',
'cityid' =>'1',
'community' =>'紫晶悦城',
'communityid'=>'1'
);
$sucess = 1;
$return = array(
'succ' =>$sucess,
'data' => $user
);
}else {
$sucess = 2;
$return = array(
'succ' =>$sucess
);
}
$b = json_encode($return);
echo "{$_GET['jsoncallback']}({$b})";
exit;
}
"Access-Control-Allow-Origin:http:www.test.com"); 代码，则会出现

XMLHttpRequest cannot load ''. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin ' ' is therefore not allowed access.

如果少了 echo "{$_GET['jsoncallback']}({$b})"; 代码
在谷歌浏览器中：Uncaught SyntaxError: Unexpected token :

在火狐浏览器中：SyntaxError: missing ; before statement