function toggleVisibility( id )
{
    var element = document.getElementById( id );

    if ( element && element.style.visibility == 'hidden' )
    {
	element.style.visibility = 'visible';
	return false;
    }
    else if ( element )
    {
	element.style.visibility = 'hidden';
	return false;
    }

    return true;
}

function hideElement( id )
{
    var element = document.getElementById( id );

    if ( element )
    {
	element.style.visibility = 'hidden';
	return false;
    }

    return true;
}