Thank you EpsiloN, but i think that will not work.
What i want is: When reloading the weapon there will be added the same number of bullets that you have fired.
Example: You shot 3 times, current_ammo + 3, ammo_available - 3
That is why i use "ammo_counter".
It works as long as you fire 18 bullets and the weapon reloads automaticly.
But if you reload in between by pressing the "r-Key" it do not work any longer, because current_ammo should be between 0 (no Ammo in Weapon) and 18 (full weapon) I think that your example don´t work like that, right?