My shoot script don't work at least not the automatic gun all my ammo disapers at ones please help me i really need this

My script:

pragma strict

var Effect : Transform; var TheDammage = 100; var shootSound : AudioClip; var ammo : int; var NoAmmoSound : AudioClip; var MaxAmmo : int = 13; var BulletHole : Transform; var FullAuto : boolean = false; var FireRate : float = 0.01; private var NextFire : float = 0.0;

function start () {

}

function Update () {

 if (Input.GetKeyDown("x"))
 {
     if (FullAuto == true)
     {
     FullAuto = false;
     }
     else
     {
     FullAuto = true;
     }
 }
 
 if (FullAuto == true)
  {
     if (Input.GetMouseButton(0)&& Time.time > NextFire)
     {
         NextFire = Time.time + FireRate;
         AMMO();
         Fire();
     }
 }
 
     if (FullAuto == false)
  {
 
 if (Input.GetMouseButtonDown(0))
 {
     AMMO();
     Fire();
 }
 }

     
     if(ammo > MaxAmmo)
        ammo = MaxAmmo;
     

}

function OnGUI() { //Shows how mush ammo you have. if(ammo > 0) { GUI.Label(Rect(20,15,25,25),ammo.ToString()); } if(ammo == 0) { GUI.Label(Rect(20,15,45,45),"No Ammo"); } }

function Fire() {

 var hit : RaycastHit;
 var ray : Ray = Camera.main.ScreenPointToRay(Vector3(Screen.width*0.5, Screen.height*0.5, 0));
                 
         
     if (Physics.Raycast (ray, hit, 100))
     {
         if(ammo > 0)
         {
         var particleClone = Instantiate(Effect, hit.point, Quaternion.LookRotation(hit.normal));
         Destroy(particleClone.gameObject, 5);
         hit.transform.SendMessage("ApplyDammage", TheDammage, SendMessageOptions.DontRequireReceiver);
         }
     }
 
 FireSound();
 
 if(ammo > 0)
 {        
     if(hit.collider.tag == "Prop")
     {
         Instantiate(BulletHole,hit.point,Quaternion.FromToRotation(Vector3.forward,hit.normal));
     }
 }

} function FireSound() {
if(ammo < 1) { if (Input.GetMouseButtonDown(0)) audio.PlayOneShot(NoAmmoSound); }

     if(ammo > 0)
     {
     if (Input.GetMouseButtonDown(0))
     audio.PlayOneShot(shootSound);
     }

}

function AMMO() { if (ammo > 0) { ammo --; } }