{
{   The purpose of this request is to validate a variable value.
{
{       FDP$VALIDATE_VARIABLE (FORM_IDENTIFIER, VARIABLE_NAME, VARIABLE_VALUE,
{         VARIABLE_STATUS, STATUS)
{
{ FORM_IDENTIFIER: (input)  The form identifier.
{
{ VARIABLE_NAME: (input)  The name of the variable to validate.
{
{ VARIABLE_VALUE: (output)  The program value to validate.
{
{ VARIABLE_STATUS: (output)  This parameter specifies the status of the
{       variable.
{
{       value:  fdc$no_error
{               fdc$invalid_integer
{               fdc$invalid_real
{               fdc$invalid_string
{
{ STATUS: (output) This parameter specifies the name of the variable to set
{       to indicate the status of the request.
{
{       condition identifiers: fde$bad_data_value
{
