function open_menu(nameid,nrsign){
	var tar = document.getElementById(nameid);
	var s = document.getElementById(nrsign);
	if(tar.style.visibility == 'visible'){
		tar.style.visibility = 'hidden';
		tar.style.display = 'none';
		s.src='../images/plus.gif';
	}
	else{
		tar.style.visibility = 'visible';
		tar.style.display = 'block';
		s.src='../images/minus.gif';
	}
	return true;
}
function close_menu(nameid){
	var tar = document.getElementById(nameid);
	if(tar.style.visibility == 'visible'){
		tar.style.visibility = 'hidden';
		tar.style.display = 'none';
	}
	else{
		return false;
	}
	return true;
}