InfoPath Dev

Here is a link to an image of an infopath document:
http://office.microsoft.com/en-us/workessentials/HA012111841033.aspx

The section that I'm particularly interested in is the stock item section. How do you create a master/detail control with a drop down as the selector rather than using those stupid selection lists that are a result of a repeating table? Please help!

If you want to use a drop-down list as a master control, then you do not want to use the Master/Detail control. Instead you just want to filter your section or table based on the selection in your drop-down list.