var W3CDOM = (document.createElement && document.getElementsByTagName);

/*	***********************************************************
 *
 *	DISPATCH: connect routines to DOM event model
 *
 */
function dispatch(targetElement,eventName,handlerName)
{ 
	if (targetElement.addEventListener) { 
		targetElement.addEventListener(eventName, function(e) { return targetElement[handlerName](e); }, false);
	} else if (targetElement.attachEvent) { 
		targetElement.attachEvent("on" + eventName, function(e) { return targetElement[handlerName](e); });
	} else { 
		var originalHandler = targetElement["on" + eventName]; 
		if (originalHandler) { 
			targetElement["on" + eventName] = function(e) { originalHandler(e); return targetElement[handlerName](e); }
		} else { 
			targetElement["on" + eventName] = function(e) { return targetElement[handlerName](e); } 
		} 
	} 
}

/*	***********************************************************
 *
 *	LANDING: display catchphrases for sidebar links
 *
 */


//  INIT: attach behaviours and set vars/statusses.
//
function landingInit()
{
	if (!W3CDOM || !document.getElementById('landnav')) return;
	
	// Grab mainnav links from DOM to attach dynmenu behaviour to.
	var land_links = document.getElementById('landnav').getElementsByTagName('a');
	
	// Loop through mainnav links to see if a corresponding submenu exists.
	for (var i = 0; i < land_links.length; i++)
	{
		// Mouseover & out voor mainnav link.
		land_links[i].targetMouseoverHandler = landingShow;
		land_links[i].targetMouseoutHandler = landingHide;
		dispatch(land_links[i], "mouseover", "targetMouseoverHandler");
		dispatch(land_links[i], "mouseout",  "targetMouseoutHandler");
	}
}

//  MAIN ROUTINES: toggle visibility of text.
//
function landingShow()
{
	var def_list = this.parentNode.getElementsByTagName('dl')[0];
	def_list.style.visibility = 'visible';
}

function landingHide()
{
	var def_list = this.parentNode.getElementsByTagName('dl')[0];
	def_list.style.visibility = 'hidden';
}


//  EVENT: attach script in window.onload event chain.
//
window.targetLandingHandler = landingInit;
dispatch(window, "load", "targetLandingHandler");