How to draw horzontal line after every material new line item wise

Hi all,

I have to redesign the sapscript.

For a invoice for every new material a horizontal line will be drawen.After that for that material all new line item will be displayed than again a horizontal line should drawn.

In dynamic how i can know how many line item will be there for the particular material.

Guranted points will be rewarded .

Regards

raj