How to use variables in SQL Reporting 2008 R2

I want to populate a combo box with a list of dates 开发者_如何转开发from a DB. Then based on user input I want to be change the Tablix to filter on only dates later than the selected date.

How can I do so?

Detailed steps will be useful.

You don't need variables: you bind any filters to the relevant control in the Parameter collection

For example, Filtering, Grouping, and Sorting Data or How to: Add a Filter to a Dataset

For something more obvious and here too