function Box_ShowHide(bid, c) {
	var b = document.getElementById(bid);
	if (b.className != 'invisible') {
		b.className = 'invisible';
		return false;
	} else {
		b.className = c;
		return true;
	}
}

function OsvitaNav_ShowHide() {
	var l = document.getElementById('OsvitaNavBtn');

	if (Box_ShowHide('OsvitaNav', 'navigation'))
		l.innerHTML='<img src="/ximages/nav_osvita_dec.png" width="11" height="11" alt="[-]" />';
	else
		l.innerHTML='<img src="/ximages/nav_osvita_inc.png" width="11" height="11" alt="[+]" />';
}