function removeEventFromObject(oObj,sEvt) {
	var oldhandler = oObj[sEvt];
	oObj[sEvt] = null;
}

function getClickedLink(ev) {
	if(!ev) { ev = window.event; }
	var clickedLink = (window.event) ? window.event.srcElement : ev.target;
	while (!clickedLink.tagName || clickedLink.tagName.toLowerCase() != "a")
		clickedLink = clickedLink.parentNode;
	return clickedLink;
}

function $() {
	var aElems = [];
	for (var i=0; i<arguments.length; i++) {
		var soElem = arguments[i];
		if (typeof soElem == 'string')
			soElem = document.getElementById(soElem);
		if (arguments.length == 1)
		{
			return soElem;
		}
		aElems.push(soElem);
	}
	return aElems;
}

function show(ev)
{
	showId = getClickedLink(ev).title;
	//alert($(showId));
	$c('abstract',$(showId),'div')[0].style.display = 'block';
	getClickedLink(ev).className = 'hide_abstract';
	removeEventFromObject(getClickedLink(ev), 'onclick');
	getClickedLink(ev).innerHTML = 'Zusammenfassung ausblenden';
	addEventToObject(getClickedLink(ev), 'onclick', hide);
}
		
function hide(ev)
{
	hideId = getClickedLink(ev).title;
	$c('abstract',$(showId),'div')[0].style.display = 'none';
	getClickedLink(ev).className = 'show_abstract';
	removeEventFromObject(getClickedLink(ev), 'onclick');
	getClickedLink(ev).innerHTML = 'Zusammenfassung anzeigen';
	addEventToObject(getClickedLink(ev), 'onclick', show);
}

function $c(sClass,oObj,sTag)
{
	oObj = oObj || document;
	if (!oObj.length) { oObj = [oObj]; }
	var aElements = [];
	for(var i = 0; i<oObj.length; i++) {
		oEl = oObj[i];
		if(oEl.getElementsByTagName) {
			oObj.children = oEl.getElementsByTagName(sTag || '*');
			for (var j = 0; j<oObj.children.length; j++) {
				oObj.child = oObj.children[j];
				if(oObj.child.className&&(new RegExp('\\b'+sClass+'\\b').test(oObj.child.className))) {
					aElements.push(oObj.child);
				}
			}
		}
	}
	return aElements;
}

function addEventToObject(oObj,sEvt,fFunc)
{
	var oldhandler = oObj[sEvt];
	oObj[sEvt] = (typeof oObj[sEvt] != 'function') ? fFunc : function(){ oldhandler(); fFunc(); };
}
	
function init()
{
	abstracts = $c('abstract',document,'div');
	for (var i=0; i < abstracts.length; i++)
	{
		abstracts[i].style.display = 'none';
	}
	links = $c('show_abstract',document,'a');
	for (var i=0; i < links.length; i++)
	{
			addEventToObject(links[i], 'onclick', show);
	}
}
	
init();
/*
function show_abstract (id)
{
	document.getElementById(id).style.visibility = 'visible';
}
*/