add_objects();

while(!$done) {
	run_callback_routines();
	update_display();
}


##</code><code>##


while(!$done) {
	check_for_collisions();
	run_callback_routines();
	update_display();
}

##</code><code>##


while(!$done) {
	run_callback_routines();
	check_for_collisions();
	update_display();
}