Changing values of form on action

Changing values of form on action

I need a value to change when the client selects from a SELECT and RADIO GROUP

  2. $(document).ready(function() {

  4. $('form').change(function(){
  5. var sum = <?php echo $precio_establecido; ?>;
  6. $('select :selected').each(function() {
  7. sum += Number($(this).val());
  8. sum = Math.round(sum*100)/100;
  9. });
  10. $("#sum").html(sum);  
  11. });
  12. }); 

I have this HTML 

  1. <select name='anch1'> <option value='10'>10 ++</option> <option value='20'>20 ++</option> <option value='30'>30 ++</option> <option value='40'>40 ++</option> <option value='50'>50 ++</option> </select> <select name='anch2'> <option value='10'>10 ++</option> <option value='20'>20 ++</option> <option value='30'>30 ++</option> <option value='40'>40 ++</option> <option value='50'>50 ++</option> </select> <select name='anch3'> <option value='10'>10 ++</option> <option value='20'>20 ++</option> <option value='30'>30 ++</option> <option value='40'>40 ++</option> <option value='50'>50 ++</option> </select>
  2. <input name="RadioGroup1" type="radio" id="RadioGroup1_3" value="0" checked>
  3. <input name="RadioGroup1" type="radio" id="RadioGroup1_2" value="210" >

Now it works perfectly when the SELECT field changes. But the radio group does not work. I tried to add  this to the selector:

select :selected, #divorradiogroup checked

but it does not work... 

Can you help me?