diff --git a/main.c b/main.c
index 4c4e27e..f478af6 100644
--- a/main.c
+++ b/main.c
@@ -1,14 +1,37 @@
 #include <gtk/gtk.h>
 
+static void
+print_hello (GtkWidget *widget,
+             gpointer   data)
+{
+  g_print("Hello World\n");
+}
+
 static void
 activate (GtkApplication* app,
           gpointer        user_data)
 {
   GtkWidget *window;
+  GtkWidget *button;
+  GtkWidget *box;
 
   window = gtk_application_window_new (app);
   gtk_window_set_title (GTK_WINDOW (window), "Window");
   gtk_window_set_default_size (GTK_WINDOW (window), 200, 200);
+
+  box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
+  gtk_widget_set_halign (box, GTK_ALIGN_CENTER);
+  gtk_widget_set_valign (box, GTK_ALIGN_CENTER);
+
+  gtk_window_set_child (GTK_WINDOW (window), box);
+
+  button = gtk_button_new_with_label ("Hello World");
+
+  g_signal_connect (button, "clicked", G_CALLBACK (print_hello), NULL);
+  g_signal_connect_swapped (button, "clicked", G_CALLBACK (gtk_window_destroy), window);
+
+  gtk_box_append (GTK_BOX (box), button);
+
   gtk_window_present (GTK_WINDOW (window));
 }