function epos(left, top)
		{
			this.left = left;
			this.top = top;
		}

		function open_menu(ref_element_id)
		{
			// input-element selecting date for 
			var ref_element = document.getElementById(ref_element_id);

			pos_x = get_element_pos(ref_element);
			pos_y = get_element_pos(document.getElementById('h_1'));

			pos_left = pos_x.left;
			pos_top  = pos_y.top+1;

			mf = document.getElementById('menu_frame');
			
			mf.style.left = pos_left + "px";
			mf.style.top = pos_top + "px";
			mf.style.visibility = 'visible';
		}
		
		function hide_menu()
		{
			document.getElementById('menu_frame').style.visibility='hidden';
		}
		
		function get_element_pos(element)
		{
			// get position of the element
			var parent=element.offsetParent;
			var pos = new epos(0,0);
			while (parent) {
				pos.left = pos.left + parent.offsetLeft;
				pos.top  = pos.top  + parent.offsetTop;
				parent=parent.offsetParent;
			}
			
			pos.left = pos.left + element.offsetLeft;
			pos.top  = pos.top + element.offsetTop;
			
			return pos;
		}
		
		function submenu_hover_in(submenuid, linkid)
		{
			var submenu=document.getElementById(submenuid);
			var link=document.getElementById(linkid);
			
			submenu.className='layout submenu_active';
			link.className='layout submenu_active';			
		}
		
		function submenu_hover_out(submenuid, linkid)
		{
			var submenu=document.getElementById(submenuid);
			var link=document.getElementById(linkid);
			
			submenu.className='layout submenu';
			link.className='layout submenu';			
		}
		
		var menu_close_to;