untermenu_status = new Array();
buffer = '';

isDefined = function(variable){ 
	return this[variable] === undefined ? false : true;
};

function untermenu(elementname) {
	buffer = untermenu_status[elementname];
	if (untermenu_status[elementname] == 0 || !isDefined("buffer")) {
		document.getElementById(elementname).style.display='block';
		untermenu_status[elementname] = 1;
	}
	else {
		document.getElementById(elementname).style.display='none';
		untermenu_status[elementname] = 0;
	}
}