title: how to calculate YTD and MTD calculations
body: <p>I have a year drop down with YTD and MTD, field named datavalue_1 and month_name, and parameter called Month_parameter. So when I select YTD from the drop down,It should display sum of datavalue_1 where [month_name]&lt;=[Month_parameter]   and when I select MTD from the drop down, it should display sum of datavalue_1 of that month.
  What I mean is, if September is selected then YTD should return the sum of datavalue_1 from January to September, and if MTD is selected then it should return sum of datavalue_1 of September.</p>
  
  <p>How do I write the calculations for this.
  Thanks in advance!!!
  Regards</p>