Set Resize limits

Hi all,

I ahave a qestion. I created a zoomin/zoom out script useing touch inputs for Vuforia AR. But I hat to have some limitiation in increasing and decreasing my object How can I do that? It whould be nice if you give an solutuin with a MAX float and MIN as float;

Thanks

This is my script:

 using UnityEngine;
 using System.Collections;
 
 public class pinch : MonoBehaviour {
 
     public float perspectiveZoomSpeed = 0.05f;        // The rate of change of the field of view in perspective mode.
     public GameObject _cube;
     public float MaxZoom;
     private Vector3 _mScale;
     private Vector3 _mStartScale;
 
 
     void Start(){
         _mStartScale = _cube.transform.localScale;
     
     }
     
     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;
 
 
             _cube.transform.localScale =   Vector3.Lerp(_mStartScale, _mStartScale * deltaMagnitudeDiff , perspectiveZoomSpeed);
 
 
         }
     }
 }