if (init == 0)
{
    if (smallrocks)
    {
        sourcelayer = "BG_Rocks_Small";
        image_blend = make_color_rgb(163, 183, 255);
    }
    depth = layer_get_depth(sourcelayer);
}
if (smallrocks)
    y -= 2;
else
    y -= 5;
if (y <= cameray())
{
    layer_set_visible(sourcelayer, 1);
    layer_y(sourcelayer, y);
    instance_destroy();
}