Deleting a Directory and All Its Contents - C#

Quick code I wrote the delete all directories named, trg, within the source directory, src.

public void DeleteDirectory(DirectoryInfo dir, string trg)
        {
            foreach (DirectoryInfo sub in dir.GetDirectories())
            {
                if (sub.Name.Equals(trg))
                {
                    foreach (FileInfo file in sub.GetFiles())
                        file.Delete();

                    sub.Delete();
                }
                else
                    DeleteDirectory(sub, trg);
            }
        }