Page 211: Table 14-3 should have "Close" as its text instead of "Hello World!"
Page 211: The code example under Listening to Events should be as follows:
function helloWorldFrame_OnLoad(frame) frame:RegisterEvent("PLAYER_TARGET_CHANGED"); end
Page 213: The code example listed under Add the Close Button Code should be as follows:
function closeButton_OnClick(frame) frame:Hide() end