My first posting!!!

I have been having issues with trying to creating a formula that will allow me to add values within a date range. I receive weekly data from timesheets and I am trying to sum only the values of a certain category type within a date range. Sample of data below:

Item Date Expnd Category Cost ($)
31-Mar-14 EXPENSE 5.36
31-Mar-14 EXPENSE 48.73
18-Apr-14 LABOR 3378.96
25-Apr-14 LABOR 844.73
25-Apr-14 LABOR 844.73
2-May-14 LABOR 4223.69
9-May-14 LABOR 1689.46
9-May-14 LABOR 1689.46

the data increase every and need to work out how much is accumulated over a date period. I have set up a drop down menu which provides me with the date ranges, beyond that I get stuck.

Please help.