Application.openurl won't work on android?

I am trying to open a simple webpage (google for example) and it works fine in editor but not on my android tablet?!?!?!?

 using UnityEngine;
 using System.Collections;
 
 public class GUITest : MonoBehaviour {
 
 
     // Use this for initialization
     public GUISkin guiskin;
 
     void Start () {
     
     }
     
     // Update is called once per frame
     void OnGUI () {
         GUI.skin = guiskin;
         if(GUI.Button (new Rect(100,100,300,100), "Test")){
             Debug.Log ("testclick");
             Application.OpenURL("www.google.com");
         }
 
     }
 }