50 10 20 30 0
<form action="beispiel_auswertungs.html" method="get">

   <input type="text" name="Wert" size="5">
   <input type="checkbox" name="Box" value="50" onClick="setze()"> 50
   <input type="radio" name="Box1" value="10" onClick="setze()"> 10
   <input type="radio" name="Box1" value="20" onClick="setze()"> 20
   <input type="radio" name="Box1" value="30" onClick="setze()"> 30
   <input type="radio" name="Box1" value="0" onClick="setze()">  0

</form>
<script type="text/javascript">
<!-- Eventhandler onClick

function setze()
{
  document.forms[0].elements[0].value="0";
  for (i=0;i<document.forms[0].elements.length;i++)
  {
   if (document.forms[0].elements[i].checked)
    document.forms[0].elements[0].value=
      parseInt(document.forms[0].elements[0].value)+
      parseInt(document.forms[0].elements[i].value)
  }
}

//-->
</script>