gtk header problems?

[randylhess netscape net]

Hello,

I have included the header file.

#include <gtk/gtk.h>

But I still get the following errors when compiling:

warning: implicit declaration of function `gtk_button_set_label'
warning: implicit declaration of function `gtk_clist_get_row_from_data'

I checked in the gtk.h file and it includes the gtkbutton.h file which 
has the gtk_button_set_label function declared in it.

Here is the code from the first function.  Maybe there is something I am 
missing.

void
change_toggle_button_label (GtkWidget *window, gchar *button)
{
 if (toggle_button_callback(window, button))
 {
   gtk_button_set_label ((GtkButton *)lookup_widget(window, button), 
"Yes");
 }
 else
 {
   gtk_button_set_label ((GtkButton *)lookup_widget(window, button), "No");
 }
}

Does the header have a problem or is there a problem with my code?

Thanks for your help,

Randy Hess