In the documentation you can find often the statement "ui.update([number])", like in the groupbox show example:
repeat
-- update for 500ms
ui.update(500)
-- hide the Groupbox
groupbox:hide()
-- update for 500ms
ui.update(500)
-- show the Groupbox
groupbox:show()
until not win.visible
However, the number does nothing. The number does not pause the update. No matter what number I enter, the user interface is always updated the same. The documentation for the function "ui.update()" does not describe any parameter.