problem with lookup_widget function

[ztoon <ztoonifik netcourrier com>]

hi
This function doesn't to compile in an application i'm doing

I have this code :

GtkWidget *w = lookup_widget(GTK_WIDGET(MainWindow), "MainWin");


error message is :

source.c:58: warning: implicit declaration of function `lookup_widget'
source.c:58: warning: initialization makes pointer from integer without a cast

How to make work lookup ??