Draw more EditorGUILayout components?

I’m trying to Draw more components when I push a button in my inspector, but they are not drawing. What am I doing wrong?

[CustomEditor(typeof(Stuff))]
public class ExampleEditor : Editor
{


		public override void OnInspectorGUI ()
		{
				EditorGUILayout.LabelField ("Stuff");
				if (GUILayout.Button ("Click")) {
						EditorGUILayout.BeginHorizontal ();
						EditorGUILayout.LabelField ("Ints");
						EditorGUILayout.IntField (0);
						EditorGUILayout.EndHorizontal ();
						Repaint ();
				}
		}
}

Thank you

GUILayout.Button(“Click”) will only be true in exactly the frame you click it. Do something like this:

       bool clicked = false;
       public override void OnInspectorGUI ()
       {
          EditorGUILayout.LabelField ("Stuff");
          if(GUILayout.Button ("Click"))
            clicked = !clicked; // button switches other stuff on and off

          if(clicked)
          {
                 EditorGUILayout.BeginHorizontal ();
                 EditorGUILayout.LabelField ("Ints");
                 numOne = EditorGUILayout.IntField (numOne);
                 EditorGUILayout.EndHorizontal ();
          }
       }