I'm trying to make the collision work. But...

Hey. Could you look at my script and tell me why it never set "isCol" to false when its not colliding?

using UnityEngine; using System.Collections;

public class PlayerMovement : MonoBehaviour {

 private float movementSpeed = 20.0f;
 private bool isCol;


 // Use this for initialization
 void Start () {
 


 }


 void OnCollisionEnter (Collision col) {
         isCol = true;
     
 }

 void OnCollisionExit (Collision col) {
         isCol = false;
     
 }

 // Update is called once per frame
 void Update () {


     if (isCol == false) {
         transform.Translate (Vector3.down * Time.deltaTime);
     }


 
     if (Input.GetKey (KeyCode.W)) {
         transform.Translate ((Vector3.forward) * movementSpeed * Time.deltaTime);
     }

     if (Input.GetKey (KeyCode.S)) {
         transform.Translate ((Vector3.back) * movementSpeed * Time.deltaTime);
     }
     if (Input.GetKey (KeyCode.A)) {
         transform.Translate ((Vector3.left) * movementSpeed * Time.deltaTime);
     }
     if (Input.GetKey (KeyCode.D)) {
         transform.Translate ((Vector3.right) * movementSpeed * Time.deltaTime);
     }