vertical lines in smartform

Hi Experts

I am print all item details in the main window for INVOICE Samrtform. After that at the bottom footer I am printing the total. Problem is I am using the table Element to print the item details, in that I selected to print the lines & boxes for header item & line items. But it is printing for up to the line items only. For example if there is only 2 line items the vertical line is printing up to 2 line items only. But I need to print the vertical lines up to the end of the main window. How can I do this?

Regards

Rajendra