I have problem in selecting radiobutton.

Dear All,

      I designed a form  for displaying questions.

  label for displaying questions and radiobutton for displaying four different answers for each  question.

My problem is,

here when i want to choose right  answer for each question.

I used radio button for each question for displaying four different answers. Any one of the radiobutton only it should get selected but for me all the radio buttons are getting selected.

So what shall I do to rectify my problem..kindly help me

LABEL

RADIOBUTTON1

RADIOBUTTON2

RADIOBUTTON3

RADIOBUTTON4

LABEL

RADIOBUTTON5

RADIOBUTTON6

RADIOBUTTON7

RADIOBUTTON8

LABEL

RADIOBUTTON9

RADIOBUTTON10

RADIOBUTTON11

RADIOBUTTON12

LABEL

RADIOBUTTON13

RADIOBUTTON14

RADIOBUTTON15

RADIOBUTTON16

LABEL

RADIOBUTTON17

RADIOBUTTON18

RADIOBUTTON19

RADIOBUTTON20