I’m trying to make it so you can only shoot when touching the left side of the screen. This will be on mobile. I figured I would just add another if parameter, but I have an error I don't know how to fix.

using UnityEngine; using System.Collections;

public class Flaregun : MonoBehaviour {

 public Rigidbody flareBullet;
 public Transform barrelEnd;
 public GameObject muzzleParticles;
 public AudioClip flareShotSound;
 public AudioClip noAmmoSound;    
 public AudioClip reloadSound;    
 public int bulletSpeed = 2000;
 public int maxSpareRounds = 5;
 public int spareRounds = 3;
 public int currentRound = 0;

 private float halfScreenWidth;

 private void Start()
 {
     halfScreenWidth = Screen.width / 2;
 }

 // Update is called once per frame
 void Update () 
 {
     
     if(Input.GetButtonDown("Fire1") && !GetComponent<Animation>().isPlaying && Input.GetButtonDown("Fire1").position.x < halfScreenWidth)
     {
         if(currentRound > 0){
             Shoot();
         }else{
             GetComponent<Animation>().Play("noAmmo");
             GetComponent<AudioSource>().PlayOneShot(noAmmoSound);
         }
     }
     /*if(Input.GetKeyDown(KeyCode.R) && !GetComponent<Animation>().isPlaying)
     {
         Reload();
         
     }*/
 
 }
 
 void Shoot()
 {
         currentRound--;
     if(currentRound <= 0){
         currentRound = 0;
     }
     
         GetComponent<Animation>().CrossFade("Shoot");
         GetComponent<AudioSource>().PlayOneShot(flareShotSound);
     
         
         Rigidbody bulletInstance;            
         bulletInstance = Instantiate(flareBullet,barrelEnd.position,barrelEnd.rotation) as Rigidbody; //INSTANTIATING THE FLARE PROJECTILE
         
         
         bulletInstance.AddForce(barrelEnd.forward * bulletSpeed); //ADDING FORWARD FORCE TO THE FLARE PROJECTILE
         
         Instantiate(muzzleParticles, barrelEnd.position,barrelEnd.rotation);    //INSTANTIATING THE GUN'S MUZZLE SPARKS    
 }
 
 void Reload()
 {
     if(spareRounds >= 1 && currentRound == 0){
         GetComponent<AudioSource>().PlayOneShot(reloadSound);            
         spareRounds--;
         currentRound++;
         GetComponent<Animation>().CrossFade("Reload");
     }
     
 }

}