How to filter dropdown list values by another dropdown list in ASP.NET, c#

Question

I have a simple question about filters. I have 4 dropdown lists which filter the data in my web application from MySQL database table. The first dropdown list is already sel

Answer 1

Filter the second dropdown datasource with selectedvalue of first dropdown control

see this article http://www.asp.net/data-access/tutorials/master-detail-filtering-with-two-dropdownlists-