Dear Annie: I've had my current job in sales for a little over two years, and during that time I've gone from part-time to full-time and gotten one promotion. I'm great at my job, to the point where some of my peers are urging me to go after a management position. I'd like to try, partly because I want to make more money (about 20% more than I made last year, bonus included). How should I make my case for a promotion? — Top Gun