Get YouTube VideoID from Url

private string GetYouTubeVideoID(string lnk)
{
   if (lnk.Contains("youtube.com") ||
       lnk.Contains("youtu.be"))
   {
       Regex YT = new Regex(@"youtu(?:\.be|be\.com)/(?:.*v(?:/|=)|(?:.*/)?)([a-zA-Z0-9-_]+)");
       Match youTube = YT.Match(lnk);
       if (youTube.Success)
       {
           _linkType = "youtube";
           return youTube.Groups[1].Value;
       }
       _linkType = "url";
       return lnk;
   }
   _linkType = "url";
   return lnk;
}