missing parameter wraper

utils.php

@@ -17,4 +17,9 @@ function error($code, $message)
   header("HTTP/ $code $message");
   die(json_encode(array("code" => intval($code), "message" => $message)));
 }
+
+function error_missing()
+{
+  error(400, "Missing Parameter");
+}
 ?>