Door Design Instructions:

First Click on the skin type you would like. (Select Skin)
Then Click on the type of Slab you like from the slabs that appear.
If the Slab Type has Door Light options, they will appear for you to click on as well.
Finally, you can select the Layout you want from the 6 layout icons above the main graphic. (Select Layout)
You can fine tune the Door Light selections with the Door Light Filters.