public function setTextSize( $front, $background = null )
	{
		#	comment
		
		if( !is_numeric( $front ) )
			throw new CaptchaException( __METHOD__ . '($arg) must be numeric' );
		
		if( !$background )
		{
			
			$this->_front_text['size'] = $front;
			$this->_background_text['size'] = $front + 10;

		}
		else
		{
			if( !is_numeric( $background ) )
				throw new CaptchaException( __METHOD__ . '($arg) must be numeric' );

			if( $front > $background )
				throw new CaptchaException( __METHOD__ . '($front, $background) $background must be greater than or equal front' );

			$this->_front_text['size'] = $front;
			$this->_background_text['size'] = $background;
		}
		
		return $this;
		# Method End
	}