HI all, I am using 15.1 and 15.2 allegro. I have a previously ddesigned board.Now I want to reroute that board.So I have deleted all the traces in the internal layers.I want top and Bottom to be rermained as same. After deleting all the traces now I want to purge all the unused vias.How can I do it? Can u please help me? Regards Chandra Kanth