how can we give permisson in c# so that no one can delete file.

private void button1_Click(object sender, EventArgs e)
      {
          string fileName = @"E:\kkk.txt";

          WindowsIdentity ident = WindowsIdentity.GetCurrent();
          WindowsPrincipal user = new WindowsPrincipal(ident);

          AddFileSecurity(fileName, user.Identity.Name,
                    FileSystemRights.Delete, AccessControlType.Deny);
      }

public static void AddFileSecurity(string fileName, string account,
          FileSystemRights rights, AccessControlType controlType)
      {

          FileSecurity fSecurity = File.GetAccessControl(fileName);

          fSecurity.AddAccessRule(new FileSystemAccessRule(account,
              rights, controlType));

        File.SetAccessControl(fileName, fSecurity);

      }