Gosh, I'm so stupid

.
Fixed, but if somebody has a problem like this here is the answer:
Code:
public Ham_Damage(id, inflictor, attacker, Float:damage, Damage)
{
if(attacker != 0){
if(get_user_weapon(attacker) == CSW_KNIFE && zwiadowca[attacker] && cs_get_user_team(attacker) != cs_get_user_team(id))
{
user_kill(id)
set_user_frags(attacker, get_user_frags(attacker)+1)
}
}
}