Gun Recoil

Hello today I have been struggling with a recoil script please help me fix this script please, thanks! Here's my shoot script preferably attach a recoil script onto to this, Im new to scripting also so explain the script please.

 var Effect : Transform;
 var TheDammage = 30;
 var SpawnTo: Transform;
 var Gun : Transform;
 var AudioShot: AudioClip;
 var muzzleFlash    : Renderer;
 var muzzleLight : Light;
 
 
 
 function Start() {
 muzzleFlash.enabled = false;
 muzzleLight.enabled = false;
 }
 function OnTriggerEnter(hit:Collider)
 {
 if(hit.gameObject.tag == "Player")
 {
 Gun.parent = SpawnTo;
 Gun.transform.position = SpawnTo.transform.position;
 Gun.transform.rotation = SpawnTo.transform.rotation;
 }
 }
 
 function Update () {
     var hit : RaycastHit;
     var ray : Ray = Camera.main.ScreenPointToRay(Vector3(Screen.width*0.52, Screen.height*0.5, 0));
     
     if ((transform.parent != null) && Input.GetMouseButtonDown(0))
     if(Input.GetButtonDown("Fire1"))
     {
         Shoot();
     }
     if ((transform.parent != null) && Input.GetMouseButtonDown(0))
     if (Input.GetMouseButtonDown(0))
     {
        if (Physics.Raycast (ray, hit, 100))
        {
         
          audio.PlayOneShot(AudioShot,0.7);
          var particleClone = Instantiate(Effect, hit.point, Quaternion.LookRotation(hit.normal));
          Destroy(particleClone.gameObject, 2);
          hit.transform.SendMessage("ApplyDammage", TheDammage, SendMessageOptions.DontRequireReceiver);
        }
     }
     }
     
     function Shoot()
 {
     
     muzzleFlash.renderer.enabled = true;
     muzzleLight.enabled = true;
     yield WaitForSeconds(0.1);
     muzzleFlash.renderer.enabled = false;
     muzzleLight.enabled = false;
 }