gtkD GUI design

[SaltySugar]

I want to do a GUI like this:
http://www.part.lt/img/f44e209eb2ccbc9dda2e6b11fa5c6317747.jpg

But I've got the following result:
http://www.part.lt/img/f4a238595048be7c23655b02477aabd8447.jpg

My Code:


import gtk.MainWindow;
import gtk.Label;
import gtk.Button;
import gtk.VBox;
import gtk.HBox;
import gtk.Entry;
import gtk.Main;

class Application : MainWindow
{
        this()
        {
                super("GtkD App");
                setDefaultSize(200, 200);
                
                HBox hBox = new HBox(false, 3);
                HBox hBox1 = new HBox(false, 3);
                VBox vBox = new VBox(false, 5);
                
                Button btnLog = new Button("LOGIN --->");
                Label lblNick = new Label("User: ");
                Entry txtNick = new Entry();
                Label lblPass = new Label("Password: ");
                Entry txtPass = new Entry();
                
                btnLog.setSizeRequest(70, 30);
                vBox.packStart(hBox, true, true, 3);
                vBox.packStart(hBox1, true, true, 3);
                
                hBox.add (lblNick);
                hBox.add (txtNick);
                hBox1.add (lblPass);
                hBox1.add (txtPass);
                vBox.add (btnLog);
                
                add(vBox);
                showAll();
        }
}
void main(string[] args)
{
        Main.init(args);
        new Application();
        Main.run();
}

Thanks.