if (northcon == 1)
{
    northcon = -1;
    layer_set_visible("TILES_Secret_North", false);
    snd_play(snd_locker);
    instance_create(0, 0, obj_shake);
    if (i_ex(northcollider))
        instance_destroy(northcollider);
}
if (southcon == 1)
{
    southcon = -1;
    layer_set_visible("TILES_Secret_South", false);
    snd_play(snd_locker);
    instance_create(0, 0, obj_shake);
    if (i_ex(southcollider))
        instance_destroy(southcollider);
}