voting using a gridview..??

[Shanksluvsuall]

hey guys i am creating a competion page.. so i allow ppl to vote .. so to display the posts i am using a gridview.. if i have another template field column in the gridview.. and try to use a radio button then??
i) how to find the row index based on the choice he selected..
ii) when i use radio buttons.. he can choose all the radio buttons too in the gridview.. i.e. all radio buttons are independent and are unknown of the others' existence i want it to be in such a way tat he can choose only one radio button.... in a grid view.. plss help...i ll be grateful to u .. plss friends