[Unity3d] GUI Button Image

1. public Texture2D center;
2.  
3. void Start() {
4. ...
5. center = (Texture2D) Resources.Load("center", typeof(Texture2D)); // Assigns a texture named "center.png" to a Texture2D(center).
6.  
7. ...
8. }
9.  
10. void OnGUI() {
11. ...
12. if (GUI.Button (new Rect (850, 570, 32, 32), new GUIContent(center))) {
13. ...
14. }
15. ...
16. }