link error about flex++ using with g++

[jinjun guo]

I have a simple lex file "foo.l":

//-----------begin---------------------
%{
#include <iostream>
using namespace std;
%}
string [a-zA-Z]+
%%
{string} { cout << "A string is found!\n"; }
//-------------end---------------------------


When I execute the following commands:

    %> flex++ foo.l
    %> g++ lex.yy.cc -lfl

It always reports:

/usr/lib/libfl.a(libmain.o): In function `main':
libmain.o(.text+0x11): undefined reference to `yylex'
collect2: ld returned 1 exit status

----------My question-------------------------
What is wrong with my code?
------------------------------------------------

// some information
flex++ version 2.5.4
g++ version 3.2.3


Thanks a lot.

JJ







__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com