Fnd_Pref_SetReal

            Fnd_Pref_SetReal (name; value {; scope})

              Parameter                 Type              Description
              name                      Text              Name of the preference item
              value                     Real              The new preference value
              scope                     Longint           The preference’s scope (optional)

            This routine stores a real number value.
              Fnd_Pref_SetReal ("ExchangeRate";$rate_r)

            If no scope is specified, the preference is stored as a local preference. Pass a third parameter to specify the
            scope of the preference:
              Fnd_Pref_SetReal ("ExchangeRate";$rate_r;Fnd_Pref_Shared )

            A preference’s scope should not be changed. Doing so may cause unpredictable results.