I'm working on a registration form (I'll be the only user). The idea is to select which fee is appropriate (Single / Couple / Student), add child fee (if any) and have the total appear in a text box. The first part is working, thanks to a code snippet I found online, but I can't figure out how to add in the fee for children. Here's the code. Any help gratefully appreciated.
HTML Code:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
<title>Registration Form</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<script type="text/javascript">
function total(){
  var form = document.forms['myform'];
  for(var i=0; i<form.elements.length; i++){
      form.elements[i].onclick = function(){
        for(var i=0,total=0; i<this.form.elements.length; i++){
          var input = this.form.elements[i];
          if(input.type.match(/(checkbox|radio)/i) && input.checked){
            total += input.value/1;
		   this.form.total.value = total.toFixed(2);

  form.onsubmit = function(){ 
    for(var i=0; i<this.elements.length; i++){
    var input = this.elements[i];
        input.value = input.id+'/'+input.value;
} window.onload = total;

<form action="<?php echo $editFormAction; ?>" method="POST" name="myform">
<input type="radio" name="fee" id="Adult" value=55.00> Adult $55 <br>
<input type="radio" name="fee" id="Couple" value=95.00> Couple $95 <br>
<input type="radio" name="fee" id="Student" value=25.00> Student $25<br><br>

Number of Children: <input name="childnum" type="text" id="Children" value="" size="3"> 
&nbsp;&nbsp; Cost: $&nbsp;<input name="fee" type="text" id="childfee" value="0" size="8"><br>
         ($10 per child to cover cost of lunch)<br>
          Total: <input name="total" id="total" type="text" onFocus="this.blur();" size="8" readonly>
		  Paid: $<input name="amountpaid" id="amountpaid" type="text" size="8">
        <input name="Submit" type="submit" class="button"  value="Register"></td>