public function addTab( $label, $content, $fragmentKey = NULL )
	{
		if( is_null( $fragmentKey ) )
		{
			$this->tabs[]	= $label;
			$this->divs[]	= $content;
		}
		else
		{
			if( isset( $this->tabs[$fragmentKey] ) )
				throw new Exception( 'Tab with Fragment ID "'.$fragmentKey.'" is already set' );
			$this->tabs[$fragmentKey]	= $label;
			$this->divs[$fragmentKey]	= $content;
		}
	}