Trying to compile the following:

//include files
#include <stdlib.h> // Provides EXIT_SUCCESS
#include <winbgim.h> // Borland Graphics Interface

int main()
{
initwindow(WIDTH,HEIGHT);
getch();

return EXIT_SUCCESS;
}

I'm getting "undefined reference to 'initwindow'"
my compile statement is
g++ foo.cxx

I'm sure I'm forgetting to link in a file or something, but I can't find any place that will comprehensively show me what I'm doing. Thanks in advance!
--Brandon