This question is an extension of this one:
http://stackoverflow.com/questions/2359238/calculate-order-price-by-date-selection-value
I'm trying to make a conference registration page based off the previous page, which passes the variables(name, email, price) to my organization's outdated shopping cart using javascript. I'm also using Seminar Registration by CSSTricks (http://css-tricks.com/examples/SeminarRegTutorial/)
Currently, my proceed to payment button produces an 'element is undefined' error on line 298(same thing on unresolved previous question, linked above^):
 switch (document.Information.amount.value) {
Any help would be greatly appreciated. I'm at my wits end with this. Here is the page:
     <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
 <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
  <title>Seminar Registration Form with jQuery</title>
  <link rel="stylesheet" type="text/css" href="css/style.css" media="screen" />
  <script src="js/jquery-1.2.6.js" type="text/javascript" charset="utf-8"></script>
  <script src="js/form-fun.jquery.js" type="text/javascript" charset="utf-8"></script>
  <!--[if IE]>
   <style type="text/css">
    legend { 
     position: relative;
     top: -30px;
    }
    fieldset {
     margin: 30px 10px 0 0;
    }
   </style>
   <script type="text/javascript">
    $(function(){
     $("#step_2 legend").css({ opacity: 0.5 });
     $("#step_3 legend").css({ opacity: 0.5 });
    });
   </script>
  <![endif]-->
 </head>
 <body>
  <div id="page-wrap">
   <h1>Conference <span>Registration</span></h1>
   <form action="#" method="post">
    <fieldset id="step_1">
     <legend>Step 1</legend>
     <label for="num_attendees">
      How cool are you?
     </label>
     <select id="amount">
      <option id="0" value="0">Please Choose</option>
      <option id="prof" value="90.00">Professional</option>
      <option id="grad" value="55.00">Graduate Student</option>
     </select>
     <br />
     <div id="attendee_1_wrap" class="name_wrap push">
      <h3>Who are you?</h3>
      <p>
      <label for="FirstName">
        First Name:
      </label>
      <input type="text" id="FirstName" class="name_input"></input>
      </p>
      <p>
      <label for="LastName">
        Last Name:
      </label>
      <input type="text" id="LastName" class="name_input"></input>
      </p>
      <p>
      <label for="OfficialTitle">
        Official Title:
      </label>
      <input type="text" id="OfficialTitle" class="name_input"></input>
      </p>
   <h3>How do we find you?</h3>
     <label for="email">Email: </label>
 <input id="email" name="email" class="required email" />
 </p>
 <p>
 <label for="Address">Street Address: </label><input name="Address" id="Address" type="text" size="20" maxlength="75" />
 </p>
 <p>
 <label for="City">City: </label><input name="City" id="City" />
 </p>
 <p>
 <label for="State">State: </label><select name="State" id="State">
 <option selected value="IL">IL</option>
  <option value="AL">AL</option>
  <option value="AK">AK</option>
  <option value="AZ">AZ</option>
  <option value="AR">AR</option>
  <option value="CA">CA</option>
  <option value="CO">CO</option>
  <option value="CT">CT</option>
  <option value="DE">DE</option>
  <option value="DC">DC</option>
  <option value="FL">FL</option>
  <option value="GA">GA</option>
  <option value="HI">HI</option>
  <option value="ID">ID</option>
  <option value="IN">IN</option>
  <option value="IA">IA</option>
  <option value="KS">KS</option>
  <option value="KY">KY</option>
  <option value="LA">LA</option>
  <option value="ME">ME</option>
  <option value="MD">MD</option>
  <option value="MA">MA</option>
  <option value="MI">MI</option>
  <option value="MN">MN</option>
  <option value="MS">MS</option>
  <option value="MO">MO</option>
  <option value="MT">MT</option>
  <option value="NE">NE</option>
  <option value="NV">NV</option>
  <option value="NH">NH</option>
  <option value="NJ">NJ</option>
  <option value="NM">NM</option>
  <option value="NY">NY</option>
  <option value="NC">NC</option>
  <option value="ND">ND</option>
  <option value="OH">OH</option>
  <option value="OK">OK</option>
  <option value="OR">OR</option>
  <option value="PA">PA</option>
  <option value="RI">RI</option>
  <option value="SC">SC</option>
  <option value="SD">SD</option>
  <option value="TN">TN</option>
  <option value="TX">TX</option>
  <option value="UT">UT</option>
  <option value="VT">VT</option>
  <option value="VA">VA</option>
  <option value="WA">WA</option>
  <option value="WV">WV</option>
  <option value="WI">WI</option>
  <option value="WY">WY</option>
 </select>
 </p>
 <p>
 <label for="Zip">Zip Code: </label><input name="Zip" id="Zip" type="text" value="" size="5" maxlength="10"  />
 </p>
 <p>
 <label for="Phone">Telephone: </label><input name="Phone" id="Phone" type="text" value="" size="10" maxlength="13" />
 </p>
     </div>
    </fieldset>
    <fieldset id="step_2">
     <legend>Step 2</legend>
     <p>
      Do you work in Higher Education?
     </p>
     <input type="radio" id="company_name_toggle_on" name="company_name_toggle_group"></input>
     <label for="company_name_toggle_on">Yes</label>
      
     <input type="radio" id="company_name_toggle_off" name="company_name_toggle_group"></input>
     <label for="company_name_toggle_off">No</label>
     <div id="company_name_wrap">
      <label for="company_name">
       Which School?
      </label>
      <input type="text" id="company_name"></input>
     </div>
     <div class="push">   
      <p>
       Will anyone in your group require special accommodations?
      </p>
      <input type="radio" id="special_accommodations_toggle_on" name="special_accommodations_toggle"></input>
      <label for="special_accommodations_toggle_on">Yes</label>
       
      <input type="radio" id="special_accommodations_toggle_off" name="special_accommodations_toggle"></input>
      <label for="special_accommodations_toggle_off">No</label>
     </div>
     <div id="special_accommodations_wrap">
      <label for="special_accomodations_text">
       Please explain below:
      </label>
      <textarea rows="10" cols="10" id="special_accomodations_text"></textarea>
     </div>
    </fieldset>
    <fieldset id="step_3">
     <legend>Step 3</legend>
     <label for="rock">
      Are you ready to rock?
     </label>
     <input type="checkbox" id="rock"></input>
    <p>
     <INPUT onclick="javascript:PaymentButtonClick()" type=button value="Proceed to payment" name=PaymentButton>
     <img src="images/visa1.gif" />
     <img src="images/mastercard1.gif" />
    </p>
    </fieldset>
   </form>
  </div>
 <FORM name="emailForm" action="mailform.asp" method=post">
 <INPUT type="hidden" value="Conference Registration" name="mf_subject">
 <INPUT type="hidden" value="Yes" name="mf_email_results"> 
 <INPUT type="hidden" title="" style="BACKGROUND-COLOR: #ffffa0" size="20" name="num_attendees">
 <INPUT type="hidden" title="" style="BACKGROUND-COLOR: #ffffa0" size="17" name="FirstName">
 <INPUT type="hidden" title="" style="BACKGROUND-COLOR: #ffffa0" size="22" name="LastName">
 <INPUT type="hidden" title="" style="BACKGROUND-COLOR: #ffffff" size="64" name="OfficialTitle">
 <INPUT type="hidden" title="" style="BACKGROUND-COLOR: #ffffff" size="40" name="email">
 <INPUT type="hidden" title="" style="BACKGROUND-COLOR: #ffffff" size="48" name="Address">
 <INPUT type="hidden" title="" style="BACKGROUND-COLOR: #ffffa0" size="17" name="City">
 <INPUT type="hidden" title="" style="BACKGROUND-COLOR: #ffffa0" size="17" name="State">
 <INPUT type="hidden" title="" style="BACKGROUND-COLOR: #ffffa0" size="17" name="Zip">
 <INPUT type="hidden" title="" style="BACKGROUND-COLOR: #ffffa0" size="17" name="Phone">
 <INPUT type="hidden" title="" style="BACKGROUND-COLOR: #ffffa0" size="17" name="company_name">
 <INPUT type="hidden" title="" style="BACKGROUND-COLOR: #ffffff" size="20" name="special_accomodations_text">
 <INPUT type="hidden" value="
[email protected]" name="mf_from">
 <INPUT type="hidden" value="
[email protected]" name="mf_to">
 </FORM>
 <FORM name="addform" action="https://webcluster.niu.edu/CreditCard/servlet/Shopping_Cart_Add_Item_Servlet" method="post">
 <INPUT type="hidden" value="orient" name="Dept_ID">
 <INPUT type="hidden" value="
Orientation" name="Product_Name">
 <INPUT type="hidden" value="z000000" name="Product_Code">
 <INPUT type="hidden" value="" name="amount">
 <INPUT type="hidden" value="/orientation/index.shtml" name="return_link">
 <INPUT type="hidden" value="http://www.niu.edu" name="return_server">
 <INPUT type="hidden" value="1" name="quantity"> <INPUT type="hidden" value="0" name="tax">
 <INPUT type="hidden" value="0" name="ship"> <INPUT type="hidden" value="DQ83225" name="sale_id">
 <INPUT type="hidden" value="XXXXXX" name="sale_acct">
 </FORM>
 <SCRIPT language="Javascript"> 
 function PaymentButtonClick() {
 switch (document.Information.amount.value) {
     case 'prof':
         document.Information.amount.value = 90.00;
         break;
     case 'grad':
         document.Information.amount.value = 55.00;
         break;
 }
     document.addform.Product_Name.value = document.Information.FirstName.value + ","+ 
                                           document.Information.LastName.value+","+
                                           document.Information.OfficialTitle.value+","+
                                           document.Information.email.name+","+","+
                                           document.Information.Address.value+ "," + 
                                           document.Information.City.value+ "," + 
                                           document.Information.State.value+ "," + 
                                           document.Information.Zip.value+ "," + 
                                           document.Information.Phone.value+ "," + 
                                           document.Information.company_name.value+ "," + 
                                           document.Information.special_accomodations_text.value;
     document.addform.Product_Code.value = document.Information.LastName.value;
     if ((document.Information.UCheck.checked==true) &&
         (document.Information.altDate1.value != "") && 
         (document.Information.altDate1.value != "x")) {
         if (document.Information.StudentLastName.value != "" ||
             document.Information.StudentFirstName.value != "" ||
             document.Information.StudentID.value != "" )  {
                 document.addform.submit();
         }
         else { 
             alert("Please enter missing information");
         } 
     }
 }
 </SCRIPT>
 </body>
 </html>