jsonp 에러

<!-- HTML -->

<form id="urllink" action="/test">

<input type="hidden" name="mid" value="test">

</form>

<script>

var urllink = $("#urllink").attr("action");
var urllink = $("#urllink").serialize();

function test(){

$.ajax({
type:"POST",
url : urllink,
data : formData ,
dataType : "jsonp",
jsonpCallback : "myCallback",
success: function(data) {
   alert(data[msg]);
},
error: function(xhr) {
 console.log('실패 - ', xhr);
}
});

}

</script>

<button onClick="">테스트</button>

<!-- PHP -->

<?php
$callback = $_GET['callback'];

$arr = array("test" => "test");
$json_val =  json_encode($arr);
echo $callback."(".$json_val.")";
?>

ParseError #0 "syntax error, unexpected ':', expecting ',' or ';'" in files/cache/opage/240.none.cache.php on line 2

정상적으로 출력 될려면 어떻게 해야할까요..