getJSON跨域SyntaxError问题分析

$(".check_mobile").click(function(){
var mobile = $('.mobile').val();
$.getJSON("http://www.test.com/user.php?mobile="+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);
}
});
});

<?php
if($_GET){
$mobile = $_GET['mobile'];
if ($mobile == 'XXXX') {
$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
);
}
echo json_encode($return);
}
?>

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

<?php
header("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;
}
?>