function toggleDiv(selectedDiv) {
	var divs = document.getElementById('contents').getElementsByTagName('div');

	for (var i=0; i<divs.length; i++) {
		var divId = divs[i].id;

		if (divId != "") {
			document.getElementById(divId).style.display = "none";
			document.getElementById(divId).style.visibility = "hidden";
		}
	}
	
	document.getElementById(selectedDiv).style.display = "block";
	document.getElementById(selectedDiv).style.visibility = "visible";
}