/**
 * Drilldown Menu Show/Hide Handler
 *
 * To use the drill-down menu use "triggers" and "submenus". Submenus are UL's
 * that are hidden by default. When clicking on a trigger link, a submenu is
 * revealed.
 *
 * Assign ID's to the submenu and class it as "submenu". 
 * Assign the trigger link that opens the submenu to the same ID as the submenu,
 * and postfix "_trigger" to that ID, and class the trigger link as "closed".
 *
 * So: my_submenu is the submenu UL, and my_submenu_trigger is the trigger.
 *
 * Example:
 *
 * <link href="dd_menu.css" rel="stylesheet" type="text/css" />
 * <script type="text/javascript" src="dd_menu.js"></script>
 * <div class="dd_menu">
 * <ul>
 *   <li><a id="my_submenu_trigger" class="closed" href="javascript:void(0);" onclick="dd_sh('my_submenu');">My sub menu &hellip;</a></li>
 *		 <ul id="my_submenu" class="submenu">
 *			 <li><a href="javascript:void(0);">This link exists in the submenu</a></li>
 *			 <li><a href="javascript:void(0);">Another link in the submenu</a></li>
 *     </ul>
 *   <li><a href="javascript:void(0);">A regular (non-trigger) link</a></li>
 * </ul>
 * </div>
 *
 * Use javascript:void(0); instead of "#" for null links as using "#" will move
 * the window to the top of the document...
 *
 * Requirements: 
 *  - dd_menu.js
 *  - dd_menu.css
 *	- arr_rt.gif (right pointing arrow)
 *  - arr_dn.gif (down pointing arrow)
 *
 * @param  string		what	ID of what to show or hide
 * @author R. Christy <rchristy@bcbsm.com>
 * @return bool	true (always)
 */
function dd_sh(what)
{
	e = document.getElementById(what);
	l = document.getElementById(what + '_trigger');
	switch(e.style.display)
	{
		case 'none':
			e.style.display = 'block';
			l.className='open';
			break;
		case 'block':
			e.style.display = 'none';
			l.className='closed';
			break;
		default:
			e.style.display = 'block';
			l.className='open';
			break;
	}
	// l.blur();
	return true;
} //dd_sh();