I have created a spreadsheet that once you put in your bankroll, your desired amount for the month, the lines, the win/loss amounts, it keeps track and tells you how much to bet to keep you on target for your monthly winnings. If you want a copy I have uploaded it to this link. Hopefully this works since I have not tried sharing a file this way before. Please use it, or change it to what you need. It's based on a top play per day, but you can use it the way some do by chasing games during the day example 1pm, 4pm, 8 pm games. It also has a Euro to American odds converter on the side for those that play soccer or have books that use Euro odds. It's in Excel 97-2003 format since.
It's free and enjoy. I just wanted to give back a bit from what I have learned here. I have named it retirexls.xls since that is my goal with it. I am working on a MLB totals chase system that can be used with it. I will post the results of that soon.
Here is the link, if it works.
retirexls.xls