problems exporting haskell functions

[Juan Ignacio Garcia Garcia]

Hello, I have tried to export haskell functions, but I haven't been able to compile anything and obtain a executable file. My program has two parts. 
 - Haskell part:
      module Hex where
      fh :: Int -> Int
      foreign export "f"  fh :: Int -> Int
      fh x = 7    

 - C part:
      #include <stdio.h>
      #include <stdlib.h> 
      extern int f(int x);

      int main( ){
      int a;
      a = f(5);
      printf("%d\n",a);
      return 0;
      }

I have tried to compile it using the glasgow-extensions, but it has links problems.
Does anyone know if there is something wrong in my program?
Does anyone know where I can find a little example program where haskell functions are exported?

Thanks,

J.I. García