Hi Andrei, Thanks for the answer, but it only changes the error. Now I get: warning: assignment discards qualifiers from pointer target type Ah, BTW I'm using gcc -o calc main.c `pkg-config --cflags --libs gtk+-2.0` main.c: In function `on_vezes_clicked': main.c:217: warning: assignment discards qualifiers from pointer target type main.c:218: warning: assignment discards qualifiers from pointer target type --------------------- void on_vezes_clicked (GtkButton *button, gpointer user_data) { CALC *elem; (CALC *) elem = user_data; oper1 = gtk_entry_get_text(GTK_ENTRY(elem->op1)); oper2 = gtk_entry_get_text(GTK_ENTRY(elem->op2)); ... ires = iope1 * iope2; sprintf(result,"%4d", ires); /* Here I get A Segfault :( */ gtk_entry_set_text(GTK_ENTRY(elem->res), result); } -------------------------------- >) oper1 = gtk_wentry_get_text (GTK_ENTRY (elem->op1)); >) oper2 = gtk_wentry_get_text (GTK_ENTRY (elem->op2)); Cheers, LEslie -- Outside of a dog, a book is a man's best friend. Inside a dog it's too dark to read. Groucho Marx _______________________________________________ gtk-list@xxxxxxxxx http://mail.gnome.org/mailman/listinfo/gtk-list