Help me It keeps giving me error Unknown identifier 'Fire'

 var Projectile: Transform;
 var firerate: float = 0.3;
 private var nextFire: float = 0.5;
 var Ammo: int = 30;
 var empty: boolean = false;
 
 function Update () {
 
 if (Input.GetButton("Fire1")&&Time.time > nextFire)
 {
     if(Ammo > 0){
     Fire();
     }
     else{
     return;
     }
     
 }
 
 if(Input.GetKeyUp("r")){
 if(empty){
     Reload();
     }
 }
 
 if(Ammo <= 0){
     audio.playOnAwake();
 empty = true;
 }
 else{
 empty = false;
 }
 
 }
 fuction Fire(){
 
 audio.PlayOneShot();
     nextFire = Time.time + fireRate;
     
     var shot = Instantiate(Projectile, transform.position, Quaternion.identity);
     shot.rigidbody.AddForce (transform.forward * 3000);
     Ammo--;
 }
 
 fuction OnGUI(){
     GUI.Box (Rect(Screen.width - 100, 20, 100, 80), "");
     GUI.Label (Rect (Screen.width - 100, 35, 90, 20), "Ammo:" + Ammo);
     GUI.Label (Rect (Screen.width - 100, 20, 90, 20), "Health" + PlayerHealth.currentHealth);
 
 if(empty){
 GUI.contentColor = Color.red;
 GUI.Label (Rect (Screen.width - 100, 50, 90, 20), "RELOAD");
 
     }
 }
 
 @script ExecuteInEditMode()