Use Ctrl+JKHL to control page scrolling in Skim

private.xml

<?xml version="1.0"?>
<root>

  <appdef>
    <appname>Skim</appname>
    <equal>net.sourceforge.skim-app.skim</equal>
  </appdef>

  <item>
    <name>Use Ctrl+JKHL to control page scrolling in Skim</name>
    <identifier>private.jkhl_in_skim</identifier>
    <only>Skim</only>
    <autogen>
      __KeyToKey__ KeyCode::J, ModifierFlag::CONTROL_L,
      KeyCode::CURSOR_DOWN
    </autogen>
    <autogen>
      __KeyToKey__ KeyCode::K, ModifierFlag::CONTROL_L,
      KeyCode::CURSOR_UP
    </autogen>
    <autogen>
      __KeyToKey__ KeyCode::H, ModifierFlag::CONTROL_L,
      KeyCode::PAGEUP
    </autogen>
    <autogen>
      __KeyToKey__ KeyCode::L, ModifierFlag::CONTROL_L,
      KeyCode::PAGEDOWN
    </autogen>
  </item>
</root>