[Pottus]

1) Do it like this

pawn Код:

switch(weaponid)
{
    case 24: { amount = 110; }
    case 22: { amount = 10; }
    ......
}

2)

pawn Код:

new Float:HP;
new Float:Armour;
GetPlayerHealth(playerid, HP);
GetPlayerArmour(playerid, Armour);

Armour -= amount;
HP -= Armour;
if(Armour > 0.0) SetPlayerArmour(playerid, Armour);
else
{
    SetPlayerArmour(playerid, 0.0);
    if(HP <= 0.0) SetPlayerHealth(playerid, 0.0);
    else SetPlayerHealth(playerid, HP);
}