Pinch not working

Hi, i have code for scale my objects using pinch. But it’s not working, can anyone tell me please?

using UnityEngine;
using System.Collections;

public class Zoom_Button : MonoBehaviour 
{
	private Transform Table_Transform = null;
	
	public float scaleFactor = 0.5f;        // The rate of change of the scale
	
	public float minScale = 0.6f;
	public float maxScale = 2.0f;
	
	void Update()
	{
		// If there are two touches on the device...
		if (Input.touchCount == 2) {
			// Store both touches.
			Touch touchZero = Input.GetTouch (0);
			Touch touchOne = Input.GetTouch (1);
			
			// Find the position in the previous frame of each touch.
			Vector2 touchZeroPrevPos = touchZero.position - touchZero.deltaPosition;
			Vector2 touchOnePrevPos = touchOne.position - touchOne.deltaPosition;
			
			// Find the magnitude of the vector (the distance) between the touches in each frame.
			float prevTouchDeltaMag = (touchZeroPrevPos - touchOnePrevPos).magnitude;
			float touchDeltaMag = (touchZero.position - touchOne.position).magnitude;
			
			// Find the difference in the distances between each frame.
			float deltaMagnitudeDiff = prevTouchDeltaMag - touchDeltaMag;
			
			Table_Transform.localScale += new Vector3(deltaMagnitudeDiff * scaleFactor, deltaMagnitudeDiff * scaleFactor, deltaMagnitudeDiff * scaleFactor); 
			
			float Table_X, Table_Y, Table_Z;
			
			Table_X = Mathf.Clamp(Table_Transform.localScale.x, minScale, maxScale);
			Table_Y = Mathf.Clamp(Table_Transform.localScale.y, minScale, maxScale);
			Table_Z = Mathf.Clamp(Table_Transform.localScale.z, minScale, maxScale);
			
			Table_Transform.localScale = new Vector3(Table_X, Table_Y, Table_Z);
		} 
	}
}

This is the code. Here it didn’t show any errors.

-Prasanna

You need to assign a transform to your Table_Transform variable otherwise it will be null always. Just assign your transform of your intended object in Start() to your Table_Transform variable.