battlearray_client/Assets/Scripts/UI/GUIButton.cs

using UnityEngine;
using System.Collections;

public class GUIButton : MonoBehaviour {

	public Texture textureOut;
	public Texture textureOver;

	// Use this for initialization
	void OnMouseEnter () 
	{
		if(textureOver != null)
			GetComponent<Renderer>().material.mainTexture = textureOver;
	}
	
	// Update is called once per frame
	void OnMouseExit () 
	{
		if(textureOut != null)
			GetComponent<Renderer>().material.mainTexture = textureOut;
	}
}