var isShown="content";
function showIt(x) {
	document.getElementById(x).style.display = "";
	if (document.getElementById(x).style.visibility == 'visible') {
	} else {
		document.getElementById(isShown).style.visibility = 'hidden';
		document.getElementById(x).style.visibility = 'visible';
		isShown=x;
	}
}