I was tried the above problem, I was done binding data to DropdownList. there not a problem, I wrote under SelectedIndexechanged event of DropDownList, When selecting the item in DropdownList , based on that display the data in different controls.
The problem is again we can select the same Item in DropDownList doen't go to the postback to server, we can select the another item, that will fire and also we select next the previous item is fire, The main problem is when we select the same item again and again doen't fire.I want fire the same item again and again of DropDownList.
for example: I can bind the Country names to dropdownList. I wrote code under dropdownList event. If we can select the India occurs the postback then related states coming. But here problem is again we can select same name like India. It doen't fire the event.