function changeBackground(element, url){
	if (url) {
		element.style.backgroundImage='url('+url+')';
	} else {
		element.style.backgroundImage='none';
	}
}
function showPicture(pictureName){
	window.open(pictureName,"gallery",null);
}
function changeCursorStyle(on_off) {
	if ((document.body)&&(document.body.style)) {		
		document.body.style.cursor = (on_off)? 'hand' : 'default';
	}
}