>>>Actually, you could leave them, and eliminate only when field is empty, i.e. normal lines would still have spaces between. Do you want to know how?
>>>
>>
>>Yes, I do.
>
>You place 'invisible' vertical line (color=white) besides the field so line's height covers both field height and extra space, and you mark the line the same way as the field: i.e. remove line when blank and print when...

Thanks. I think I used a similar trick with invisible line but for the slightly different purpose.

Nice to know this trick.