Gui basics Error: need ;

Ok, I’m embarrassed to ask this question, but i dont find any solution.

I have try to make my first GUI Basics.
Open Unity, create C# script, double-click, open it with monodevelop, control C on GUI Basic example

 using UnityEngine;
 using System.Collections;
 public class GUITest : MonoBehaviour {
 void OnGUI () {
   if (GUI.Button (new Rect (10,10,150,100), "I am a button")) {
     print ("You clicked the button!");
   }
 }
 }

Save all and play

I found this error message: expected an ; between 1-6

Now, i have make the same with javascript example and this work fine.
What is the problem with c#?
I have make more other script c# and they work. Only GUI basics example dont work.

(O,o)‘’

Make sure that your file name and class name are the same: “GUITest”