You forgot to escape (\") a quotationmark (") on line 43
causing an error.
After having fixed that I get a form, with option buttons.
When I click for example the 4th button and hit submit, it prints
seems to work.
It is possible that your server doesn't understand "$HTTP_GET_VARS['radiobutton'];"
you could try using "$POST['radiobutton'];" or "$REQUEST['radiobutton'];"