4.6 UI Button Press, how?

I wish to move player with force thru rigidbody component, have a script on player object

//example move left
    void MoveLeft(float step)
        {
            Debug.Log("go left");
            //	transform.Translate (Vector3.left * step);
            rigidbody.AddForce(Vector3.left * step, ForceMode.Impulse);
    
        }

//movement swich
    public void Movement(string direction)
        {
            switch (direction.ToLowerInvariant())
            {
                case "up":
                    MoveForward(Step);
                    break;
                case "down":
                    MoveBack(Step);
                    break;
                case "left":
                    MoveLeft(Step);
                    break;
                case "right":
                    MoveRight(Step);
                    break;
                default:
                    break;
            }
    
        }

Looking for a way to make button press from event trigger in unity 4.6,

call Movement() with direction string as parameter and button press which will keep calling MoveLeft()

until button is released.

Which event in event trigger simulates button press?

PointerDown is triggered when clicking down.

public class Test: MonoBehaviour, IPointerDownHandler, IPointerUpHandler
{
public void OnPointerDown(PointerEventData eventData)
{
UserIsInPress = true;
}

    public void OnPointerUp(PointerEventData eventData)
    {
        UserIsInPress = false;
    }

    public bool UserIsInPress ;

	void Update () {
	    if (UserIsInPress )
	    {
            Debug.Log("In touch!");
	    }
	}
}