{
{ The purpose of this request is to read one menu string, addressed by
{ position in the menu list.  A pointer is returned, which if not NIL,
{ will point to Screen Manager's copy of the text.  A NIL value means
{ that the user had not previously provided any string at all.
{
{       CSP$GET_MENU_ITEM_STRING (MENU_ITEM_NUMBER, MENU_STRING, STATUS)
{
{ MENU_ITEM_NUMBER: (input)  This identifies the menu item whose string is
{       to be read and copied back to the caller.
{
{ MENU_STRING: (output)  This will receive the text of the menu string.
{
{ STATUS: (output) This receives any error codes.
{
{       condition_identifiers:  none at release 1.4.1
