function display(previous, next) {
	var hide = document.getElementById(previous).style.display;
	var display = document.getElementById(next).style.display;
	if (display == "block") {
		document.getElementById(previous).style.display = "block";
		document.getElementById(next).style.display = "none";
	}else{
		document.getElementById(previous).style.display = "none";
		document.getElementById(next).style.display = "block";
	}
}

function backgroundOver(id, img) {
	document.getElementById(id).style.background = "url("+img+")";
}