public function buildCalendar( $cell_class = NULL, $heading_span = NULL )
	{
		$time	= mktime( 0, 0, 0, $this->getOption( 'show_month'), 1, $this->getOption( 'show_year' ) );
		$offset	= date( 'w', $time )-1;
		if( $offset < 0 )
			$offset += 7;
		$days	= date( "t", $time );
		$weeks	= ceil( ( $days + $offset ) / 7 );
		$d	= 1;
		$lines	= array();
		for( $w=0; $w<$weeks; $w++ )
		{
			$cells	= array();
			for( $i=0; $i<7; $i++ )
			{
				if( $offset )
				{
					$cells[]	= $this->buildCell( 0, $cell_class );
					$offset --;
				}
				else if( $d > $days )
					$cells[]	= $this->buildCell( 0, $cell_class );
				else
				{
					$cells[]	= $this->buildCell( $d, $cell_class );
					$d++;
				}
				$line	= implode( "", $cells );
			}
			$lines[]	= UI_HTML_Tag::create( "div", $line, array( 'class' => 'day-week' ) );
		}
		$lines		= implode( "\n\t  ", $lines );
		$days		= UI_HTML_Tag::create( "div", $lines, array( 'class' => "days" ) );
		$heading	= $this->buildHeading( $heading_span );
		$weekdays	= $this->buildWeekDays();
		$code		= $this->getCode( $heading, $weekdays, $days );
		return $code;
	}