There are many ways to do this, here are two:
(1) Add a few hidden boolean controls and assign each a function key using [advanced..key navigation]. Now create a case for each "value changed" and set the tab accordingly. (See Example 1).
(2) Use the "key down?" event and switch the tab if certain function keys have been pressed (See example 2). Make sure to use filter events and discard the function keys. If you don't, you'll also get the help window every time you press F1.