```
the selectedLine
the selectedLine of listField
the selectedLine of popupButton
```
Values returned:
* for the selectedLine, a line expression that indicates the line of a field or the Message box in which a range of characters is currently highlighted
* for the selectedLine of listField, a line expression that indicates the lines of a list field in which the characters are currently highlighted
* for the selectedLine of popupButton, a line expression that evaluates to the line number in a popup button’s contents indicating the current selection
If nothing is selected, the selectedLine returns empty.
If a field isn't currently a list field but it was in the past, and a selection had been made when it was a list field, the selectedLine returns the most recent selection.
The line expression returned has the following forms:
```
line i of {card|bkgnd} field n
line i of {card|bkgnd} button n
line x to y of {card|bkgnd} field n
```
where i is the line number and n is the number of a popup button or a field, and x to y is a range of lines in a list field.