public class theMovingPlatform : MonoBehaviour {
          
         public enum XYZ { X, Y }
         public XYZ direction;
         public float distance = 1.0f;
         public float velocity = 1.0f;
         private Vector3 velocityVector;
          
         private float startXPosition;
         private float startYPosition;
          
         private float currentXPosition;
         private float currentYPosition;
         private float endXPosition;
         private float endYPosition;
         private float projection;
         private const float epsilon = 0.0000000001f;
          
         void Start() {
                 velocityVector = GameObject.FindGameObjectWithTag("movp").rigidbody.velocity;
                 startXPosition = transform.position.x;
                 startYPosition = transform.position.y;
                  
                 endXPosition = startXPosition + distance;
                 endYPosition = startYPosition + distance;
         }
          
         private bool ShouldGoForward()
     {
         return currentXPosition == startXPosition || currentXPosition < endXPosition;
     }
          
         void Update () {
                  
                 currentXPosition = transform.position.x;
                 currentYPosition = transform.position.y;
                  
                 switch( direction.ToString() ){
                 case "X":
                         float x = Time.deltaTime * ( ShouldGoForward() ? velocity : - velocity );
                         transform.Translate(new Vector3( x, 0, 0));
                         if (( endXPosition - currentXPosition ) < epsilon ) {
                    velocityVector = - velocityVector
                         }
                         break;
                 case "Y":
                         break;
                 }
    }
}