public void useDns() {

   // Create a DnsPermission instance.
   DnsPermission permission = new DnsPermission(PermissionState.Unrestricted);

   // Check for permission.
   permission.Demand();
   // Create a SecurityElement object to hold XML encoding of the DnsPermission instance.
   SecurityElement securityElementObj = permission.ToXml();    
   Console.WriteLine("Tag, Attributes and Values of 'DnsPermission' instance :");
   Console.WriteLine("\n\tTag :" + securityElementObj.Tag);
   // Print the attributes and values.
   PrintKeysAndValues(securityElementObj.Attributes);
}

private void PrintKeysAndValues(Hashtable myList) {
   // Get the enumerator that can iterate through the hash table.
   IDictionaryEnumerator myEnumerator = myList.GetEnumerator();
   Console.WriteLine("\n\t-KEY-\t-VALUE-");
   while (myEnumerator.MoveNext())
      Console.WriteLine("\t{0}:\t{1}", myEnumerator.Key, myEnumerator.Value);
   Console.WriteLine();
}