{
{   The purpose of this procedure is to turn on the flag
{ that identifies the given socket to be listen socket. It
{ also stores the given port number in the job socket record.
{
{       NLP$SK_UPDATE_LISTEN_FLAG (SOCKET_ID, PORT)
{
{ SOCKET_ID: (input) This parameter specifies the socket identifier.
{
{ PORT: (input) This parameter specifies the port number to
{       which the given socket is bound.
{
