Stop 2D camera X axis movement if equal to one of two coordinates

This camera script follows a transform (in this case th eplayer), but at the end of each side of the level i would like it to stop X movement if the transform it follows is at a certain position (to stop camera tracking off the level).

Here is the current script.

 using UnityEngine;
 using System.Collections;
 
 public class Camera2DFollow : MonoBehaviour {
     
     public Transform target;
     public float damping = 1;
     public float lookAheadFactor = 3;
     public float lookAheadReturnSpeed = 0.5f;
     public float lookAheadMoveThreshold = 0.1f;
     
     float offsetZ;
     Vector3 lastTargetPosition;
     Vector3 currentVelocity;
     Vector3 lookAheadPos;
     
     // Use this for initialization
     void Start () {
         lastTargetPosition = target.position;
         offsetZ = (transform.position - target.position).z;
         transform.parent = null;
     }
     
     // Update is called once per frame
     void Update () {
 
         // only update lookahead pos if accelerating or changed direction
         float xMoveDelta = (target.position - lastTargetPosition).x;
         
         bool updateLookAheadTarget = Mathf.Abs (xMoveDelta) > lookAheadMoveThreshold;
         
         if (updateLookAheadTarget) {
             lookAheadPos = lookAheadFactor * Vector3.right * Mathf.Sign (xMoveDelta);
         } else {
             lookAheadPos = Vector3.MoveTowards (lookAheadPos, Vector3.zero, Time.deltaTime * lookAheadReturnSpeed);    
         }
         
         Vector3 aheadTargetPos = target.position + lookAheadPos + Vector3.forward * offsetZ;
         Vector3 newPos = Vector3.SmoothDamp (transform.position, aheadTargetPos, ref currentVelocity, damping);
         
         transform.position = newPos;
         
         lastTargetPosition = target.position;
 
     }
 }