Help with unity form.Addfield

Hello you all

I'm really stuck with something i don't see why it is not working.

My goal is to send a POST variable from unity to a php file. The php file is working fine and when i submit a POST with an regular HTML form it is working. But not when i send it from unity.

Here is the code (i am using a example from unity itself)

using UnityEngine; using System.Collections; using UnityEngine.Networking;

 public class FormSender : MonoBehaviour
 {
 
 public string discipline;
 
 void Start()
 {
     StartCoroutine(Upload());
 }
 
 IEnumerator Upload()
 {
     WWWForm form = new WWWForm();
     form.AddField("Discipline", discipline);
 
     UnityWebRequest www = UnityWebRequest.Post("myworkingform.php", form);
     yield return www.SendWebRequest();
 
     if (www.isNetworkError || www.isHttpError)
     {
         Debug.Log(www.error);
     }
     else
     {
         Debug.Log("Form upload complete!");
     }
 }
 }

And in my php file i retrieve it like this: $discipline = $_POST['Discipline'];

(i don;t think it is in the php because with a regular HTML form it is working fine).

I really dont see what i am doing wrong.

Can someone help me??

Thnx