rand = function(r)
{
	return (int)(Math.random() * r);
}

make_floor = function(y)
{
	f = Floor_top - y;
	if(f % 5 == 0)
	{
		if(f % 250 == 0)
		{
			x1 = 16;
			x2 = WIDTH * 16 - 16;
			frame = 1;
		}
		else
		{
			w = (WIDTH - 11);
			fvec = (rand(2) * 2 - 1) * (rand((int)(w / 4)) + (int)(w / 4));
			fpos = ((int)(w / 2) + fvec + w) % w;
			r1 = rand(3);
			r2 = rand(3);
			x1 = (fpos + 5 - r1 - 2) * 16 + 1;
			x2 = (fpos + 5 + r2 + 3) * 16 + 1;
			frame = 2 + r1 + r2;
			// 2 -> 5
			// 8 -> 11
		}

		set_floor_l(y, x1);
		set_floor_r(y, x2);
		Floor_index++;
		eval("floor_".concat(Floor_index)).gotoAndStop(frame);
//		eval("floor_".concat(Floor_index))._width = x2 - x1;
		eval("floor_".concat(Floor_index))._x = x1;
		eval("floor_".concat(Floor_index))._y = y * 16;
		if(Floor_index == 5) Floor_index = 0;
		return;
	}
	else
	{
		set_floor_l(y, WIDTH * 16);
		set_floor_r(y, 0);
	}
}

scroll_up = function()
{
	var y;

	for(y = 0; y < 5; y++) eval("floor_".concat(y + 1))._y += 16;
	Floor_top++;
	if(--Map_index < 0) Map_index = HEIGHT - 1;
	make_floor(0);
}

get_floor_l = function(y) { return Floor_L[ (y + Map_index) % HEIGHT ]; }
get_floor_r = function(y) { return Floor_R[ (y + Map_index) % HEIGHT ]; }
set_floor_l = function(y, v) { Floor_L[ (y + Map_index) % HEIGHT ] = v; }
set_floor_r = function(y, v) { Floor_R[ (y + Map_index) % HEIGHT ] = v; }

Floor_L = new Array(HEIGHT);
Floor_R = new Array(HEIGHT);

Floor_top = HEIGHT - 4;
Map_index = 0;
var t = 4;
for(y = 0; y < HEIGHT; y++)
{
	if((Floor_top - y) % 5 == 0) Floor_index = t--;
	make_floor(y);
}
Floor_index = 0;
Score = 0;
gameover_label._visible = false;
form_label._visible = false;