You might have discovered a bug. I'm sure that people more knowledgeable than I am, will put me straight on this.
Initially, I thought the obvious place to go was to use this sequence with your object:
Action > Triggers > Advanced > Key Press
While I've successfully used the Key Press before, when I tried to apply F4 to the trigger, it would not stick. In fact none of the function keys would stick.
Next step, the Help Files. This is what I found:
Quote:
Add the Key Press trigger to your Actions Organiser, as described in Creating and Editing Actions
. The Key Press tab will automatically appear when you add the trigger.
2. Use the Any Key option when you want any key on your keyboard to act as the trigger.
Note:
The only exceptions to the any key rule are: the Esc key (which is reserved to exit a publication), the F10 key and the Windows key (which are reserved for other operations).
This specifically states that you can't use the F10 key with the Any Key options, but it is not clear whether this exclusion applies the the use of Specific Keys.
Quote:
3. Use the Specific Key = option when you want to specify the key on the keyboard that the user must press to act as the trigger. Press the actual key (or combination of keys) that you want to use as the trigger. The keys you press are shown in the edit box. This will activate the Use Modifiers panel – see next point.
4. Tick the Shift, Ctrl or Alt boxes in the Use Modifiers panel if the user is required to hold down these keys as they press the key you have entered in the Key Pressed= option. To select one or more modifier, tick the checkbox beside the name. To cancel the selection, click again, so that it is no longer ticked.
Notes:
In most cases you will ignore the Modifier tab and move straight to step 5 below.
You cannot use the Alt modifier with function (F1 etc) keys.
I read this as at least an implication that the function keys, other than in combination with Alt, and perhaps the F10 key, can be used with the Key Press trigger.
This response doesn't help you, but perhaps it raises issues that someone at DW can clarify.