Accessing Booleans from other scripts

Hi im trying to get the hang of changing bools and ints from other scripts. in my case im just trying to change the selected to either 1 or 0. The grid highlight script is attached to multiple cubes who are the children of a empty game object named "Pad"

using UnityEngine; using System.Collections;

 public class MainGUI : MonoBehaviour {
     
     public GridHighlight script;
     
     // Use this for initialization
     void Start () 
     
     {
     
           script = gameObject.GetComponent<GridHighlight>();
         
         
     }
     
     // Update is called once per frame
     void Update () 
     {
     
         
         
         
     }
     
     void OnGUI()
     {
     
         if(GUI.Button(new Rect(20, 20, 100, 20), "Cube"))
         {
             script.selected = 0;
             
         }
 
         if(GUI.Button(new Rect(20, 40, 100, 20), "Turret"))
         {
             script.selected = 1;
             
         }
         
     }
 }