Date Difference on having condition on Dates.

Hi,

I am trying to display number of days between two dates :
I have two date columns(Joining_Date, Resigned_Date) in EMPtable and have created Independent Dimdate table and created slicer for Dimdate .
Now i want to get datediff between [Joining_Date] and Dimdate from 'date slicer' having condition on Resigned_Date.

Below is the table Having  Columns empid, joing_date, Resigned_date,

here Dimdate[date] is the selected date from filter.

I want to create measure DateDifference to calculate number of days between  'joining date' and 'dimdate' for empids whose 'Resigned_Date is greater than Dimdate or Resigned not present'.

can someone please help me to get this done