how to insert next value of the list in cokkies as i click the button

i want to save the next value of the list in cookies as i click the button it will work but there is prblom is that it will not get the next value when i click the button means when i click button one time then it get first value and when i click it scnd time then it will also get first value and when i click it thrid time then it will get scnd value the problem is that. and i want that i click it scnd time then it will get scnd value not a first value.
my code is

Response.Cookies("myfeedback")("ques_id") = rbl_ques.SelectedItem.ToString
        MsgBox(Server.HtmlEncode(Request.Cookies("myfeedback")("ques_id".ToString)))

where rbl_ques is the radio button list