Start off by starting a new image, 300×200 in size with white background. Next, draw a fairly large rectangle that takes up most of the image. Put a light gray background on it. You also want a 1 Pixel hard black border around it. Then create a new layer and using the rounded rectangle tool, put three equally sized rounded rectangles for the tabs on the top. Choose a slightly darker gray for it.
Using the Layer’s tab, gray the layer with the three rectangles behind the layer with the large, gray rectangle so they start looking like tabs. Then using any font, and black color, place the text on top of the tabs. I used BitDust2 font, size 16, all caps. It should look similar to the picture on the left.
Great, at this point select Edit – Select All then press Edit – Copy. Now go to the frames tab, which should be on the same pallete as the Layers tab. Press the Add Frame Button 
then press Edit – Paste which puts the same thing on this frame. Do the same thing again for Frame 3. Each frame represents each time each tab is on the top.
Alright, now go back to the First frame. Ctrl+Left Click the first left tab and the large rectangle, then select Modify Combin- e – Union. It might change the interior color to white, but you can change it back to gray using the color tab. Then click on the second frame and do this same step with the middle tab, and then do it again for the third frame using the third tab.
If you want you can go to the Effects tab and add an inner bevel to each of the tabs as well as the main tab with the rectangle; I used 2, Flat, Highlighted for the big rectangle with 75% opacity and 2, Flat, Raised for the little tabs with 75% opacity. Thats it folks. If you have any questions, please post them.
