{
{    Determines if the specified kety exists in the template file.
{
{       AVP$DETERMINE_IF_KEY_EXISTS (KEY, KEY_EXISTS, FILE_INFORMATION, STATUS)
{
{ KEY: (input) Key to be checked.
{
{ KEY_EXISTS: (output) Boolean value that specifies whether the specified key
{       was found in the template file.
{
{ FILE_INFORMATION: (output) Record used by the template file manager to hold
{       information about the template file.
{
{ STATUS: (output) Variable in which the completion status is returned.
{       CONDITIONS:
{             None
{
