function show_menu(self, menu) {
	obj = document.getElementById(menu);
	obj.style.visibility = 'visible';
}

function hide_menu(menu) {
	obj = document.getElementById(menu);
	obj.style.visibility = 'hidden';
}

function show_sub_menu(self, menu) {
	obj = document.getElementById(menu);
	if (obj.style.left == '') {
		coord1 = findPos(obj.parentNode);
		coord2 = findPos(obj.parentNode.parentNode);
		obj.style.left = self.offsetWidth + 'px';
		obj.style.top = coord1[1] - coord2[1] - 1 + 'px';
	}

	obj.style.visibility = 'visible';
}

function hide_sub_menu(menu) {
	obj = document.getElementById(menu);
	obj.style.visibility = 'hidden';
}

function findPos(obj) {
	var curleft = curtop = 0;
	
	if (obj.offsetParent) {
		do {
			curleft += obj.offsetLeft;
			curtop += obj.offsetTop;
		} while (obj = obj.offsetParent);
		
		return [curleft,curtop];
	}
}