Database table design issue

Question

I have User into my application and each user has assigned (District,Tehsil,UC,Villages) these are cascade in nature means
1-District contains tehsils
2-Tehsil contains ucs
3-Ucs contains villages 




Now i have place checkboxes and they are populating right based on selected , but when i de select or select another districts the previous checkbox result set lost due to post back.


My second question please suggest me a database structure for that