when Player collide with pad become child of pad

I want the player to walk across moving pads. I want him to become a child of the pad so that when the pad moves the other way, the player doesn't fall off. I also want it so that when the key W is pressed the player is no longer a child of the pad. Can anyone help. this is what i have so far:

using UnityEngine; using System.Collections;

public class playerStay : MonoBehaviour {

public GameObject Pad;

public GameObject Player;

 void OnHit(Transform Pad)
 {
     Quaternion randomRotation = Quaternion.Euler(0f, 0f, Random.Range(0f, 360f));
     Instantiate(Pad, transform.position, randomRotation);
     GameObject go = Instantiate(Player, transform.position, transform.rotation) as GameObject;
     go.transform.parent = Pad;
 }

}