Actually, this may still be possible with Designer.
While I don't know exactly what you mean by "step-action tables" and don't know what AcroForm API calls you were using to do this in PDF Forms, you can most likely still do this in an XFA form
which is rendered to PDF (which implies that Acrobat is the only application which will host the form):
In any event on any XFA object, you have access to the following object:
event.target
In Acrobat, this happens to be the
Acrobat Document object which represents the form -- on the AcroForm layer.
From there, you should be able to use most of the AcroForm functions and properties you were used to using prior to switching to XFA forms.
While there are techniques you could use in Designer to build your own tooltip-like object which becomes visible only when the mouse hovers over an object on a form, there are currently some z-order bugs in Acrobat that'll prevent that sort of solution from working nicely (which is too bad because with this solution, you could've made really rich tooltips -- some even that change dynamically depending on the data loaded into a form!). For example, some fields are always drawn above other fields, regardless of their position in the XFA object hierarchy of a form, which means that your tooltip object would always be partially obstructed. Hopefully these bugs will be addressed in a future release of Acrobat.
In the mean time, if you can remember the script for your old AcroForm-based tooltips and your form is only ever hosted by Acrobat, then I suggest you stick with AcroForms to address this problem.
Stefan
Adobe Systems
