title: To create dynamic dropdown list in excel 2013
body: <p>I have one sheet containing the table name customer_id and Project_id.For each customer id various projects are displayed.when i try to create data validation by selecting all those it is not coming.for ex.
  Customer_id Project_id
  1             1.1
  1             1.2
  2             2.2
  2             2.3
  and like that.please tell me some solution.</p>