dropdown list selection in asp.net

Question

hi friends iam new this topic

iam using asp.net aspx page iam desiging 3 dropdowns.

first for countries, second for states, third for districts  at run time iam selecting country from dropdownlist  now i want display that country corresponding

states only  in states dropdownlist after that iam selecting state from dropdown i want to display that state corresponding districts only in districts dropdown list.


please help meeeeeeeeeee friends...
please......