Bob, in the bottim right corner of the draft page, where the total salary, amount left you can spend, and amount you can spend per player is listed, there is the option to change salary level. You click that and choose $100 million.
This league, however, has now filled. I would suggest that you stay at $80 million and enter an autoleague, but feel free to ask a lot of questions on the board, whether about which players to use or how to do things. There is a ton of knowledge on this board and people enjoy sharing it.