Help With Excel

Hello,

I'm not sure quite how to get my spreadsheet to do what I need it to do. I have two tabs set up in the workbook; the first tab has a list of dates in column A, and a list of values in column B. In the second tab I need to set it up so that if I enter a range of dates from column A it will display the sum of the values in column B within that same range. So for example, if I want to know the total distance covered between September 9 and September 18, I can input 9/9/2009 in one cell, input 9/18/2009 in another cell, and then a third cell will tell me the distance covered between those days.

I don't know very much about the formulas in Excel, or using macros, so I really need some help...

Thanks