var which_color = "white";

function switch_colors()
{
	building_elt = document.getElementById('building_swap');
	
	if(which_color == "white")
	{
		building_elt.src = "images/building_red.jpg";
		which_color = "red";
	}
	else if(which_color == "red")
	{
		building_elt.src = "images/building_white.jpg";
		which_color = "white";
	}
}