Code:

var video_mode= 8;
var video_screen= 1;
var video_depth= 32;

include <level_loader_top.wdl>;
include <level_loader_car.wdl>;

string level1_wmb= <carmovesnd.wmb>;
string level2_wmb= <top_move_test.wmb>;

bmap back_pcx = <mrcode.pcx>;
bmap mouse_pcx = <cursor.pcx>;

bmap imBack = <back.pcx>;
bmap imBackOn = <back_on.pcx>;
bmap imBackOver = <back_ovr.pcx>;
bmap imCar3d = <car3d.pcx>;
bmap imCar3dOn = <car3d_on.pcx>;
bmap imCar3dOver = <car3d_ovr.pcx>;
bmap imExitOn = <exit_on.pcx>;
bmap imExitOff = <exit_off.pcx>;
bmap imExitOver = <exit_ovr.pcx>;
bmap imTopSpinner = <top_spinner.pcx>;
bmap imTopSpinnerOn = <topspinner_on.pcx>;
bmap imTopSpinnerOver = <topspinner_ovr.pcx>;

/************************************
fMouseCLoop
*************************************/
function fMouseCLoop() {
	proc_kill(4);
	mouse_map = mouse_pcx;
	while(1) {
		if (mouse_mode > 0) {
			mouse_pos.x = mouse_cursor.x;
			mouse_pos.y = mouse_cursor.y;
		}
		wait(1);
	}
}

panel back_pan {
	pos_x= 0;
	pos_y= 0;
	bmap= back_pcx;
	flags= visible;
}
panel button1_pan {
	pos_x = 350;
	pos_y = 250;
	button = 0, 0, imTopSpinnerOn, imTopSpinner, imTopSpinnerOver, load_lvl1, null, null;
	layer= 2;
	flags= visible;
}
panel button2_pan {
	pos_x = 350;
	pos_y = 350;
	button = 0, 0, imgCar3dOn, imgCar3d, imCar3dOver, load_lvl2,null,null;
	layer= 2;
	flags= visible;
}
panel exit_pan {
	pos_x = 350;
	pos_y = 450;
	button = 0, 0, imExitOn, imExitOff, imExitOver, exit, null,null;
	layer= 2;
	flags= visible;
}
panel back_button {
	pos_x = 0;
	pos_y = 0;
	button = 0, 0, imBackOn, imBack, imBackOver, go_back,null,null;
	layer= 3;
}

function load_lvl1() {
	wait(1);
	button1_pan.visible= off;
	wait(1);
	button2_pan.visible= off;
	wait(1);
	exit_pan.visible= off;
	wait(1);
	back_pan.visible= off;
	wait(1);
	back_button.visible= on;
	wait(2);
	level_load (level2_wmb);
	wait(1);
	camera.x= 0;
	camera.y= -876;
	camera.z= 664;
	camera.pan= 90;
	camera.tilt= -62;
	camera.roll= 0;
}

function load_lvl2() {
	wait(1);
	button2_pan.visible= off;
	wait(1);
	button1_pan.visible= off;
	wait(1);
	exit_pan.visible= off;
	wait(1);
	back_pan.visible= off;
	wait(1);
	back_button.visible= on;
	wait(2);
	level_load (level1_wmb);
	wait(2);
	camera.x= -714;
	camera.y= 0;
	camera.z= 845;
	camera.pan= 360;
	camera.tilt= -71;
	camera.roll= 0;
}

function exit() {
	sys_exit (null);
}

function go_back() {
	wait(1);
	back_pan.visible= on;
	wait(1);
	button1_pan.visible= on;
	wait(1);
	button2_pan.visible= on;
	wait(1);
	exit_pan.visible= on;
	wait(1);
	back_button.visible= off;
} 
/************************************
uiFreshen
*************************************/
function uiFreshen() {
	var w; 
	var h; 
	var posX; 
	var posY;
	var offset; offset = 10;
	//imCar3d is the new standard for fresh ui
	w = bmap_width(imCar3d);
	h = bmap_height(imCar3d);
	posX = int(screen_size.x / 2 - w / 2);
	posY = int(screen_size.y / 2 - ((h * 3 + offset * 2) / 2));		//exit button is bigger but shouldn't be
	button1_pan.pos_x = posX;
	button1_pan.pos_y = posY;
	posY += offset;
	button2_pan.pos_x = posX;
	button2_pan.pos_y = posY;
	posY += offset;
	exit_pan.pos_x = posX;
	exit_pan.pos_y = posY;
}
/************************************
main
*************************************/
function main() {
	//wait(3);
	uiFreshen();
	fMouseCLoop();
	mouse_mode = 2;
}