+ SessionWindow *win = (SessionWindow *)frontend;
+ va_list ap;
+ char *msg;
+ NSAlert *alert;
+
+ va_start(ap, p);
+ msg = dupvprintf(p, ap);
+ va_end(ap);
+
+ alert = [[NSAlert alloc] init];
+ [alert setInformativeText:[NSString stringWithCString:msg]];
+ [alert addButtonWithTitle:@"Proceed"];
+ [win startAlert:alert withCallback:connection_fatal_callback
+ andCtx:win];