how to make second layout xml file in android with graphical tab?

i'm developing android in eclipse. i have a main.xml file which has a graphical layout tab so you can preview the layout. i'm wanting to create开发者_StackOverflow中文版 a second layout file for a different activity but when i create the xml layout file there is no graphical layout tab to preview the layout. how can i do this? thanks

Make sure you open the layout XML in Eclipse using the "Android Layout Editor": right-click (or if on a Mac, ctrl-click) the layout file, then select "Open With..." and "Android Layout Editor".