cygwin에서 컴파일할때 에러가 납니다..

$ gcc yang.c -o yang `pkg-config --cflags gtk+-2.0`
yang.c: In function ‘main’:
yang.c:8:11: error: ‘gtkwidget’ undeclared (first use in this function)
yang.c:8:11: note: each undeclared identifier is reported only once for each function it appears in
yang.c:8:22: error: ‘window’ undeclared (first use in this function)
yang.c:10:22: error: ‘label’ undeclared (first use in this function)
yang.c:14:36: error: ‘gtk_window_toplevel’ undeclared (first use in this function)

gtk프로그래밍 연습중인데.. 음..어디가 문제인지 모르겠내요.
cygwin을 다시깔아버렸는데.. ㅠ
#include
int main( int argc,char *argv[] )

{
gtkwidget *window;

gtkwidget *label;

gtk_init (&argc, &argv);

window = gtk_window_new (gtk_window_toplevel);

label = gtk_label_new ("hello world");

gtk_container_add (gtk_container(window), label);

gtk_widget_show (label);

gtk_widget_show (window);

gtk_main ();

return(0);

}
소스는 예제 이구욤.. 어디가문제일까요..