Screen support doesn't work

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http://stackoverflow.com – When i design my app it covers all screen but when i run it i see that it doesn't cover all screen so it becomes bigger for my emulator.I have used screen-support like this <supports-screens android:anyDensity="true" android:largeScreens="true" android:normalScreens="true" android:resizeable="true" android:smallScreens="true" /> but the problem is still exists.I don't know where i'm making a mistake.Thanks in advance for your help. (HowTos)