Add line to last text box in a detail group conditionally

[CrystalProcessor]

What is a good way to locate the last detail of a group, so a text box can be formatted to underline it? Ideally the output will look like this:

RP Header
PH
GH1 A
GH2
Details 123
Details 123
Details 123
___________
GF2
GF1 A
GH1 B
GF2
Details 123
Details 123
Details 123
___________
GF2
GF1 B

Thank you!

 

[lbass]

Insert a detail_b section and, instead of a text box, insert a line in it. Then go into the section expert->detail_b->suppress->x+2 and enter:

not onlastrecord and
{table.group2field}=next({table.group2field})

-LB

 

[CrystalProcessor]

Thank you for the suggestion. In the end, I put a top line on the group below the details section. Next time, I will try your method.