How to drag object along with dragging touch?

I want to drag my player on dragging of touch but only on x-axis (left and right) and on z-axis (up and down) but limited to 10 to 16 on x-axis and -20 to -23 on z-axis.

  1. when user drag finger on left, player should move left in x-axis.
  2. when user drag finger on right, player should move right in x-axis.
  3. when user drag finger to up, player should move left in z-axis.
  4. when user drag finger to down, player should move right in z-axis

I used this code but it only can move object once on every swipe. i want to drag my object as user dragging his finger. Please Help

 #pragma strict

 private var fp : Vector2;  // first finger position
 private var lp : Vector2;  // last finger position
 var playerposition : float;
 function Update () {

 playerposition = transform.position.x;
 for (var touch : Touch in Input.touches)
 {
  if (touch.phase == TouchPhase.Began)
  {
        fp = touch.position;
        lp = touch.position;
  }
  if (touch.phase == TouchPhase.Moved )
  {
        lp = touch.position;
  }
  if(touch.phase == TouchPhase.Ended)
  { 
        if((fp.x - lp.x) > 80) // left swipe
  {
  //if (playerposition > 20) {      
  		transform.Translate(Vector3.left * 15 * Time.deltaTime);
  		//}
  } 
  else if((fp.x - lp.x) < -80) // right swipe
  {
  //if (playerposition > 20) {
        transform.Translate(Vector3.right * 15 * Time.deltaTime);
    //    }
  }
 }
 }
 }

I’d suggest using a plugin like TouchScript. It does all the work of translating inputs into gestures for you. The gesture you need is called PanGesture. You can use it in conjunction with PressGesture and ReleaseGesture to figure out when the player is dragging and in which direction.