In my aspx page there are two dropdownlist . one for category id another for subcategory id.
when user select a category id from 1st dropdownlist i want to add all subcategory id (from SQL Server 2000 database)of that category id in 2nd dropdownlist.

Please post your reply as soon as possible

Get the categoryID on selectedindexchanged, use it as an input param to the sql for ddl2, run the sql, bind the results to ddl2.