Reloading delay problem..

  #pragma strict
  var Rounds : int;
  var Ammo : int;
  var Reloading : boolean;
  var MaxAmmo : int = 20;
  var theDammage = 100;
  var delay = 0.1;
  var timestamp = 0.0;
   function Start()
  {
  GetComponent.<Animation>().Play("Idle",PlayMode.StopAll);
  }
  function Update ()
   {
  var hit : RaycastHit;
  var ray : Ray = Camera.main.ScreenPointToRay(Vector3(Screen.width*0.5, Screen.height*0.5, 0));
  if(Rounds == 0 && Ammo == 0  )
  {
  return;
  }
  if (Ammo <= 0 && Rounds >= 0 )
  {
 reloading = true
  GetComponent.<Animation>().Play("Reload",PlayMode.StopAll);
  Reload();
  Ammo = 0;
  }
  else
  {
  if (timestamp <= Time.time && Physics.Raycast (ray, hit, 10))
  {
   timestamp = Time.time + delay;
   if(hit.collider.gameObject.tag == "Dobj")
   {
   Ammo--;
   GetComponent.<Animation>().Play("Fire",PlayMode.StopAll);
   GetComponent.<AudioSource>().Play();
   hit.transform.SendMessage("ApplyDammage", theDammage, SendMessageOptions.DontRequireReceiver);
  }
  }
  }
  }
  function Reload()
  {
   yield WaitForSeconds(1.8);
  Ammo = MaxAmmo;
  Rounds--;
  Reloading = false;
 }
 
 

When the gun reloads the value of rounds goes in negative............... please update this for reloading the gun perfectly ................thanks in advance