function popup (obj, iW, iH) {
	var winW = iW;
	var winH = iH;
	var winName = '_blank';
	var winL = (screen.width - winW) / 2;
	var winT = (screen.height - winH) / 2;
	window.open(obj.href, winName, 'location=no, toolbar=no, status=no, directories=no, scrollbars=yes, menubar=no, resizable=no, left=' + winL + ', top=' + winT +', width=' + winW + ', height=' + winH);
}

//turn given menu off
function offMenu (obj) {
	document.getElementById(obj).style.display = 'none';
}

//swap a menu
function swapMenu (obj) {
	//check if hidden and show or opposite
	if (document.getElementById(obj).style.display == 'block') {
		document.getElementById(obj).style.display = 'none';
	} else {
		document.getElementById(obj).style.display = 'block';
	}
}