public static function generateUrl($email, $size=null, $default=null)
	{
		if($size == null && isset($GLOBALS['TL_CONFIG']['gravatarSize']))
		{
			$size = $GLOBALS['TL_CONFIG']['gravatarSize'];
		}

		if($default == null)
		{
			if(isset($GLOBALS['TL_CONFIG']['gravatarDefault']))
			{
				$default = $GLOBALS['TL_CONFIG']['gravatarDefault'];
			}
		}

		$separator = '?';
		$link = static::$baseHref . md5(strtolower(trim($email)));

		if($size)
		{
			$link .= $separator . 's=' . $size;
			$separator = '&';
		}

		if($default)
		{
			$link .= $separator . 'd=' . urlencode($default);
		}

		return $link;
	}