NLS parameters in Oracle Reports

[Quoted] The Oracle documentation seems to be saying that if you would like to modify language/territory (i.e. NLS) parameters, for a report, at runtime, you can issue 'Alter Session' statements in a before report trigger.

I have tried several alter session statements in the before report trigger but they have no effect on how my data is displayed. Any ideas as to what I'm doing wrong? Here is my before trigger:

Thanks - Joe T

function BeforeReport return boolean is
begin

  SRW.DO_SQL ('ALTER SESSION SET NLS_ISO_CURRENCY = FRANCE');
  SRW.DO_SQL ('ALTER SESSION SET NLS_DATE_LANGUAGE = French');
  SRW.DO_SQL ('ALTER SESSION SET NLS_NUMERIC_CHARACTERS = '',.''');
  SRW.DO_SQL ('ALTER SESSION SET NLS_DATE_FORMAT = ''YYYY MM DD