WinMain@16

[Ernest True]

I am having trouble trying to compile a c-program, and get the error 
message that follows.
 The call to the main() function in the code is also included below.
If I do not #define TRILIBRARY,  which includes triangle.h, the program 
compiles perfectly. 
triangle.h just includes some variable definitions.
I compiled this program with gcc in July and it worked fine. Since 
then, I have updated
Windows 2000..if that means anything.
  I would appreciate any advice you can give.
Thanks,  Ernie True
true@norwich.edu

$ cd c:/cygwin/bin

$ gcc triangle.c -o triangle.exe
/usr/lib/gcc-lib/i686-pc-cygwin/3.3.3/../../../libcygwin.a(libcmain.o)(.
text+0x7d): undefined reference to `_WinMain@16'
collect2: ld returned 1 exit status

true/usr/bin
$
[Here's the code that calls main()]

#ifdef TRILIBRARY

#ifdef ANSI_DECLARATORS
void triangulate(char *triswitches, struct triangulateio *in,
                 struct triangulateio *out, struct triangulateio 
*vorout)
#else /* not ANSI_DECLARATORS */
void triangulate(triswitches, in, out, vorout)
char *triswitches;
struct triangulateio *in;
struct triangulateio *out;
struct triangulateio *vorout;
#endif /* not ANSI_DECLARATORS */

#else /* not TRILIBRARY */

#ifdef ANSI_DECLARATORS
int main(int argc, char **argv)
#else /* not ANSI_DECLARATORS */
int main(argc, argv)
int argc;
char **argv;
#endif /* not ANSI_DECLARATORS */

#endif /* not TRILIBRARY */
{