var previousMenuId = null;

function hidePopUp(id) {
	var el = document.getElementById(id);
	el.style.display= "none";
}

function showPopUp(id) {
	var previousEl = document.getElementById(previousMenuId);

	if (previousEl != null) {
		hidePopUp(previousMenuId);
	}

	previousMenuId = id;

	var el = document.getElementById(id);

	if (is_mozilla) {
		el.style.left = mousePos.x;
		el.style.top = mousePos.y;
	}
	else {
		el.style.pixelLeft = mousePos.x;
		el.style.pixelTop = mousePos.y;
	}

	el.style.display = "block";
}