[Infin1ty]

Код:

forward Float:MapAndreas_FindZ_For2DCoordEx(playerid, Float:X, Float:Y, Float:Z);
public Float:MapAndreas_FindZ_For2DCoordEx(playerid, Float:X, Float:Y, Float:Z)
{
    if(GetPlayerInterior(playerid) > 0)
    {
        return Z - 1.011;
    }
    else if(GetPlayerInterior(playerid) == 0)
    {
        return MapAndreas_FindZ_For2DCoord(X, Y, Z);
    }
    return false;
}

Give this a go. If there was an error found then it'll return false, or 0. Else, it should return the values you need. Suggestion - you probably don't want this as a function with a keyword.