function showHideTeaser(thisElement) {

	var outerElement = document.getElementById('teasers');
	var teaserElements = outerElement.getElementsByTagName('div');

	if (document.getElementById(thisElement).className == "shown") {
		document.getElementById(thisElement).className = "hidden";
		document.getElementById('plus'+thisElement).src = "images/plus.gif";
		document.getElementById('teasers').className = "hidden";
	} else {

		for (var i=0;i<teaserElements.length;i++) {
			teaserElements[i].className="hidden";
			document.getElementById('plus'+teaserElements[i].id).src = "images/plus.gif";
		}
		outerElement.className = "shown";
		document.getElementById(thisElement).className = "shown";
		document.getElementById('plus'+thisElement).src = "images/minus.gif";
	}
}

function addLoadEvent(func) {

	var oldunload = window.onload;
	if (typeof window.onload != 'function') {
		window.onload = func;
	} else {
		window.onload = function() {
			oldunload();
			func();
		}
	}

}