void cb_entry(GtkWidget* entry, gpointer data);
void cb_go(gboolean b);
void cb_download(WebKitWebView *web_view, GObject *download, gpointer user_data);
void cb_title_changed(WebKitWebView *v, WebKitWebFrame *f, const char *title, tab *t);
void cb_commit_load(WebKitWebView* page, WebKitWebFrame* frame, tab *t);