function mouseOverDoor () {
	var door = document.getElementById ('door');
	var cross = document.getElementById ('cross');
	var arrows = document.getElementById ('arrows');

	door.src = door.src.replace (/closed/, "opened");
	cross.src = cross.src.replace (/blue/, "red");
	arrows.src = arrows.src.replace (/blue/, "red");
}

function mouseOutDoor () {
	var door = document.getElementById ('door');
	var cross = document.getElementById ('cross');
	var arrows = document.getElementById ('arrows');

	door.src = door.src.replace (/opened/, "closed");
	cross.src = cross.src.replace (/red/, "blue");
	arrows.src = arrows.src.replace (/red/, "blue");
}