Paddle script for Pong-based video game for Android

Hi there, I am trying to finish my pong based video game for Android devices, but I am stuck with the Paddle script. This script is the same for Paddle1 and Paddle 2. What I want to achieve is to drag the bar in the Z axis when it is touched and leave in the position where the bar is when the touch has ended, and also what I need is to detect two touches: one for Paddle1 and other for Paddle2. This is the code I have right now:

 public static int changeDirection1;
 public static int changeDirection2;

 void Start () {
     changeDirection1 = 1;
     changeDirection2 = 1;
 }

 void Update () {
     if (Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Moved) {

         float touchDeltaPositionZ = Input.GetTouch(0).deltaPosition.y;
         float position = this.transform.position.z;    

         if (gameObject.CompareTag ("PlayerBar")) {
             if (position > -4.15f && position < 4.15f) {
                 transform.Translate (0, 0, touchDeltaPositionZ * Time.deltaTime * changeDirection1);
             } else if (position <= -4.15f) {
                 if (touchDeltaPositionZ > 0) {
                     transform.Translate (0, 0, touchDeltaPositionZ * Time.deltaTime * changeDirection1);
                 }
             } else if (position >= 4.15f) {
                 if (touchDeltaPositionZ < 0) {
                     transform.Translate (0, 0, touchDeltaPositionZ * Time.deltaTime * changeDirection1);
                 }
             }
         }
         if (gameObject.CompareTag ("Player2Bar")) {
             if (position > -4.15f && position < 4.15f) {
                 transform.Translate (0, 0, touchDeltaPositionZ * Time.deltaTime * changeDirection2);
             } else if (position <= -4.15f) {
                 if (touchDeltaPositionZ > 0) {
                     transform.Translate (0, 0, touchDeltaPositionZ * Time.deltaTime * changeDirection2);
                 }
             } else if (position >= 4.15f) {
                 if (touchDeltaPositionZ < 0) {
                     transform.Translate (0, 0, touchDeltaPositionZ * Time.deltaTime * changeDirection2);
                 }
             }
         }
     }

     if (GameController.twoPlayers) {
         if (p1bar == false && CompareTag ("PlayerBar") && FootballPlayers.bar1Hitted == false) {
             changeDirection1 = 1;
         } else if (p1bar == true && CompareTag ("PlayerBar") && FootballPlayers.bar1Hitted) {
             changeDirection1 = -1;
         }
         if (p2bar == false && CompareTag ("Player2Bar") && FootballPlayers.bar2Hitted == false) {
             changeDirection2 = 1;
         } else if (p2bar == true && CompareTag ("Player2Bar") && FootballPlayers.bar2Hitted) {
             changeDirection2 = -1;
         }
     }