Show public GameObject prefab in EditorWindow

Hi,

I want to create a window with some buttons that when clicked instantiate a prefab. I have this working using a custom inspector but now want to have all this in a separate window.

I want to select which prefabs i want to add with: public GameObject myPrefab1; public GameObject myPrefab2;

The problem is that anything I create using public GameObject doesnt show up in my window so i can not drag my prefabs.

Thanks in advance.