function navi_change (nr, menue, zustand) {
	
	var menue_basis = 'navi';
	var menue_strings = new Array();
		menue_strings[1] = '';
		menue_strings[2] = '_oben';
		
	var menue_on =	new Image(); menue_on.src	= 'images/navi_on.gif';
	var menue_off =	new Image(); menue_off.src	= 'images/navi_off.gif';
		
	var objekt_name = '';
	try { objekt_name = menue_basis + menue_strings[menue] + '_' + nr; } catch(e) {}
	
	switch (zustand) {
		case 'on': {
			try { document.getElementsByName(objekt_name)[0].src = menue_on.src; } catch(e) {}
			break;
		}
		case 'off': {
			try { document.getElementsByName(objekt_name)[0].src = menue_off.src; } catch(e) {}
			break;
		}
	}
}