{
{    The purpose of this request is to determine the number of bytes currently
{ available for the user.
{
{    This request will not be processed if there is a receive data operation in
{ progress for the connection or a task is waiting for data to become available
{ on the connection.  A request to initiate this request under either of these
{ conditions results in abnormal status with the condition
{ nae$receive_outstanding.
{
{    WARNING:  An application must receive data which has been sent by the peer
{          application within a reasonable amount of time.  If available data
{          accumulates in the connection over an extended period of time, the
{          NAM terminates the connection.
{
{       NAP$SE_GET_AVAILABLE_BYTE_COUNT (FILE_IDENTIFIER, BYTE_COUNT, STATUS)
{
{  FILE_IDENTIFIER: (input)  This parameter specifies the file access
{        identifier established when the network file was opened.
{
{  BYTE_COUNT: (output)  This parameter specifies the number of bytes of user
{        data currently available on the connection.
{
{  STATUS: (output) This parameter specifies the request status.
{       CONDITIONS:
{             ame$improper_device_class
{             ame$improper_file_id
{             ame$ring_validation_error
{             nae$connection_terminated
{             nae$improper_protocol
{             nae$receive_outstanding
{             {other BAM conditions}
{
