How to limit user input button?

i have a ball, and 3 box,
this ball will be player, i give this ball bouncy and rigidbody, and the ball will continue to jump,,
than, i use GUI Button to control the ball to the right, and left, from the box to another box,,
i use this script to do that,

Code (CSharp):

1.  
2. public float speed = 180;
3. public void RightButton() {
4. rigidbody2D.MovePosition(rigidbody2D.position + new Vector2(speed,0) * Time.deltaTime);
5. }
6. public void LeftButton() {
7. rigidbody2D.MovePosition(rigidbody2D.position + new Vector2(-speed,0) * Time.deltaTime);
8. }
9.  

but user still can spam with this script,
i want the ball can only move once per jump,
i need the ball grounded once time before it move again,
so player can feel the rhythm of the games,
so how to do that?
i didnt have any programing skill,,

 

Try something like this:

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. public class Bounce : MonoBehaviour
5. {
6.     public float speed = 180;
7.  
8.     private bool grounded = false;
9.  
10.     float rayDistance = 0.2f;
11.  
12.     private void Update()
13.     {
14.         RaycastHit2D rh = Physics2D.Raycast(transform.position, -Vector2.up, rayDistance);
15.  
16.         if (rh.collider != null && rh.collider.gameObject.tag == "Ground")
17.         {
18.             grounded = true;
19.         }
20.     }
21.  
22.     public void RightButton()
23.     {
24.         if (grounded)
25.         {
26.             rigidbody2D.MovePosition(rigidbody2D.position + new Vector2(speed, 0) * Time.deltaTime);
27.         }
28.     }
29.  
30.     public void LeftButton()
31.     {
32.         if (grounded)
33.         {
34.             rigidbody2D.MovePosition(rigidbody2D.position + new Vector2(-speed, 0) * Time.deltaTime);
35.         }
36.     }
37. }
38.