debugging of submit - added json output

submit.php

@@ -99,6 +99,10 @@ if ($stmt->execute()) {
     echo json_encode(["error" => "Error saving response."]);
 }
 
+header("Content-Type: application/json");
+echo json_encode(["debug" => "Submit script is running"]);
+exit;
+
 $conn->close();
 exit;
 ?>