FIXED.
Omg I know why there was error all the time.
Look at that:
Fixed version
if ($_GET[strona]=='ogrze') {moons_ogrze();}
Code with error
if ($_GET[strona]=='ogrze') {2moons_ogrze();}
The function name cannot begin by numeric 😛 (2moons doesnt work, moons works 🙂 )