What is the question?
<form name="Question1">
<input name="rbQuestion1" type="radio">A) possible answer 1
<input name="rbQuestion1" type="radio">B) possible answer 2
<input name="rbQuestion1" type="radio">C) possible answer 3
<input value="answer" onclick="checkQuestion" type="submit">
</form>

function checkQuestion()
{
   var QuestionChecked = false;

   for (var i=0; i<window.document.Question1.length; i++)
   {
      if (window.document.Question1.checked)
      {
         QuestionChecked = true;
      }
   }
   
   if (QuestionChecked )
   {
      if(window.document.Question1.elements[1].checked==true)
      {
         alert("right!");
      }
      else
      {
         alert("wrong!");
      }
   }
   else
   {
      alert("Please choose an existing answer!");
   }   
}

Requirements::javascript("mysite/javascript/checkQuestion.js");