function _toggle( button, block ) {
	var blc = document.getElementById( block );
	var btn = document.getElementById( button );
	if ( blc.style.display=='none') {
		blc.style.display='block';
	} else {
		blc.style.display='none';
	}
	if ( btn.className=='') {
		btn.className='active';
	} else {
		btn.className='';
	}
}