Web Forms :: Data Generation In Grid Based Upon User Drop Down Selections?

I am an newbie to this technology. I had requirement kind of thing, like, I had 5 cascading drop downs, which I created by using ajax control tool kit drop-down extenders, and used web-service to update the cascading drop downs content.

In the same form I need to create a grid, so based upon selection of the user, the grid should change dynamically, like I would like to have some examples kind of things, lets say, I had Four cascading drop- downs, like 1) Vehicles, 2) Hotels 3)Games 4) Year

And those can be sub-categorized to

1) Vehicles ----- Three Wheelers, Two Wheelers, Four Wheelers
2) Hotels -------- Five Star Hotels, Luxurious Hotels, Restaurants, Bars, Pubs
3) Games ------- Play Stations, Video Games
4) Year ----------- Manufactured or established in that particular year

so, If the user selects vehicles, then we need to show all the information regarding vehicles, and if he selects hotels , we need to get the information of vehicles, and hotels( * note, I may not be able to give u the right example, once again i want remind you that these drop downs were cascading drop downs, based upon one selection, other works) and like wise if he selects year, we need to show information of all the things manufactured or established in that particular year and here year is not a cascading drop down, and all these information is maintained in a single database table

And currently I am using Microsoft Sql Server 2008 R2, Visual Studio 2008, Using c#, ( i would be happy, if anyone gives me a code kind of thing, not mandatory, only if possible)...