Weird problem with gunscript

Shooting works fine. But when I reload, currentAmmo wont set back to maxAmmo. It just stays at 0. I have no idea what I have done wrong. Here is the code :

 var bulletSpawn : GameObject;
 var bullet : GameObject;
 var weapon : GameObject;
 var soundParent = Transform;
 var currentAmmo = 30;
 var maxAmmo = 30;
 var canFire : boolean = false;
 var fireSound : GameObject;
 var reloadSound : GameObject;
 var tacReloadSound : GameObject;
 var reloadTime : float = 1.8;
 var tacReloadTime : float = 1.5;
 
 
 
 function Update ()
 {    
    if (currentAmmo > 0)
        canFire = true;
    if (currentAmmo <= 0)
        canFire = false;
    if (currentAmmo > maxAmmo)
        currentAmmo = maxAmmo;
       
    if (Input.GetButtonDown("Fire") && canFire == true)
        IsFiring ();
              
        
    if (Input.GetButtonDown("Reload") && currentAmmo < maxAmmo)
        Reload ();   
 }
 
 function IsFiring ()
 {
    
    if (currentAmmo > 0 && canFire == true)
       {
        currentAmmo --;
        Instantiate(bullet, bulletSpawn.transform.position, bulletSpawn.transform.rotation);
        weapon.animation.PlayQueued("Fire", QueueMode.PlayNow);
        Instantiate(fireSound, bulletSpawn.transform.position, bulletSpawn.transform.rotation); 
       }
    
        
                        
    if (currentAmmo == 0)
        {
            canFire = false;
            Reload ();
        }
 
          
 }
 
 function Reload ()
 {
   
   if (currentAmmo == 0)
       {
          animation.Play("Reload");
          Instantiate(reloadSound, bulletSpawn.transform.position, bulletSpawn.transform.rotation);
          yield WaitForSeconds(reloadTime);
          canFire = true;
          currentAmmo = maxAmmo;
       }
       
                 
   if (currentAmmo > 0 && currentAmmo < maxAmmo)
       {
          currentAmmo = 0;
          animation.Play("TacReload");
          Instantiate(tacReloadSound, bulletSpawn.transform.position, bulletSpawn.transform.rotation);
          canFire = false;
          yield WaitForSeconds(tacReloadTime);
          canFire = true;
          currentAmmo = maxAmmo;
       }
 }

Please help!