Simple List property for highlighted row(s)?

In the script for a “Simple List” widget I can have the follow script (originally generated from an Action)
on mouseUp pButton, pEvent
put pEvent[“row”] into tRow
answer tRow
end mouseUp

This tells me the mouseUp is passed an array (pEvent) where the “row” element is teh row clicked. Is there a property of the Simple List widget that I can get from another object’s script (like a button script) to provide the highlighted row. For example, if I wish to use the highlighted row’s data or row number in some other script such as to delete a record or use the selected value to add a record to another table or whatever.

I see that in Actions for a Simple List, I can test if the row number is and if I make a click action delete a record, I can choose the number of the rown just clicked, but what if I want the UI model to be select a row (in a Simple List or Table [in the future}) and then click some other button (icon or label) to perform some action/script.