Q:

touch button - how to?

i'm working on Android touch button can shooting with no luck until now, my need to have button with name fire inside the canvase , can do the following:
1 - when pressed: shoot one bullet
2 - keep pressing: shoots bullets
3 - stop press: hold shooting 
i need help to update the following code with above needs:
using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class PlayerShoot : MonoBehaviour {

    public GameObject Ammo; // the shot
    GameObject FiredShot;
    public AudioClip bcgMusic;
    public List<GameObject> ShotsOnAir;

    //public AudioClip sound1;  // Use this for initialization

    void Start (){
        ShotsOnAir = new List<GameObject>();
    }

    //update is called once per frame

    void Update (){
    if (Input.GetKeyDown(KeyCode.Mouse0)){
        //if (Input.GetButtonDown("Fire1")){

            FiredShot = (GameObject)Instantiate(Ammo,transform.position,transform.rotation);
            ShotsOnAir.Add(FiredShot);
            AudioSource.PlayClipAtPoint (bcgMusic, transform.position);
        }

        if(ShotsOnAir != null){
            int i=0;

            foreach (GameObject GB in ShotsOnAir){

                ShotsOnAir[i].transform.position += ShotsOnAir[i].transform.forward * 200 * Time.deltaTime;

                i++;

            }

        }

    }

}

A:

its solved after use Input.Touch insted of Input.GetKeyDown after follow the comment by programmer

