[fpc-pascal] Error: Identifier not found "try"

[T.Guilleminot]

Hello,

The simple program below fails when compiling (2.2.2-8 and 2.2.4rc1) :

program TEST_TRY;
uses SysUtils, strutils;
 
Function IsNumber(ValueToCheck:string):boolean;
begin
  try
    StrToInt(ValueToCheck);
    IsNumber := true;
  except
    IsNumber := false;
  end;
end;
 
begin
  If IsNumber('123') then
    writeln('this is a number');
end.

tom at linux$ fpc Test_Try.pas
Free Pascal Compiler version 2.2.4rc1 [2009/01/25] for i386
Copyright (c) 1993-2008 by Florian Klaempfl
Target OS: Linux for i386
Compiling Test_Try.pas
Test_Try.pas(8,4) Error: Identifier not found "try"
Test_Try.pas(8,4) Fatal: Syntax error, ";" expected but "identifier 
STRTOINT" found
Fatal: Compilation aborted
Error: /usr/bin/ppc386 returned an error exitcode (normal if you did not 
specify a source file to be compiled)

Did I miss something obvious ?
Thanks