[Konstantinos]

I didn't really understand what you want.

pawn Код:

switch( GetPlayerSkin( playerid ) )
{
    case 280: SetPlayerSkin( playerid, 281 );
    case 281: SetPlayerSkin( playerid, 282 );
}

If the skin is 280, it sets it to 281.
If the skin is 281, it sets it to 282.