... <LinearLayout>:<LinearLayoutxmlns :android= "http://schemas .android. com/apk/res /android& quot; android: orientation="vertical" android: layout_width="fill_parent" android: layout_height="fill_parent"><! ... layouts:xmlns :android= "http://schemas .android. com/apk/res /android& quot;Defines the XML namespace for Android. You should define thisonce, on the first XML tag in the file. android: layout_width="fill_parent", ... under the Android Emulator.1.3 Running on t he EmulatorTo run your Android program, go to the Package Explorer window,right-click the HelloAndroid project, and select Run As > Android Appli-cation....