Shooting behavior

// The laser we will be shooting
public Transform laser;

// How far from the center of the ship should the laser be
public float laserDistance = .2f;

// How much time (in seconds) we should wait before 
// we can fire again
public   float   timeBetweenFires = .3f;

// If value is less than or equal 0, we can fire
private float timeTilNextFire = 0.0f;

// The buttons that we can use to shoot lasers
public List<KeyCode> shootButton;

// a foreach loop will go through each item inside of 
// shootButton and do whatever we placed in {}s using the 
// element variable to hold the item
foreach (KeyCode element in shootButton)
{
  if(Input.GetKey(element) && timeTilNextFire < 0)
  {
    timeTilNextFire = timeBetweenFires;
    ShootLaser();
    break;
  }
}

timeTilNextFire -= Time.deltaTime;

// Creates a laser and gives it an initial position in front 
// of the ship.    
void ShootLaser()
{
  // calculate the position right in front of the ship's
  // position lazerDistance units away
  float posX = this.transform.position.x + 
               (Mathf.Cos((transform.localEulerAngles.z - 90) * Mathf.Deg2Rad) * -laserDistance);
  float posY = this.transform.position.y + (Mathf.Sin((transform.localEulerAngles.z - 90) * Mathf.Deg2Rad) * -laserDistance);
  
  Instantiate(laser, new Vector3 (posX, posY, 0), this.transform.rotation);
}

using UnityEngine;
using System.Collections;

public class LaserBehaviour : MonoBehaviour 
{
  // How long the laser will live
  public float lifetime = 2.0f;

  // How fast will the laser move
  public float speed = 5.0f;


  // How much damage will this laser do if we hit an enemy
  public int damage = 1;

  // Use this for initialization
  void Start () 
  {
    // The game object that contains this component will be
    // destroyed after lifetime seconds have passed
    Destroy(gameObject, lifetime);
  }
  
  // Update is called once per frame
  void Update () 
  {
    transform.Translate(Vector3.up * Time.deltaTime * speed);
  }
}