I'm trying to write a script to process form data within a simple offline HTML page. I lifted the first four variables I'm trying to pull through as an example. I can get a simple example to work like the one found here <https://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_form_elements_index> but I'm struggling to expand it to multiple variables as below.

Am I approaching the two JavaScript functions wrong for this use?

```
<!DOCTYPE html>
<html lang="en">

<head>
<meta charset="UTF-8">
<title>JavaScript within HTML</title>

<script language = "JavaScript">
    function get_dropdown (fieldname) {
      Item = form.fieldname.selectedIndex;
      Result = form.fieldname.options[Item].text;
      return Result;
}

    function getval (form) {
      var Customer_Name = form.customer_name.value;
      var Asset_Name = form.asset_name.value;
      var Asset_Attribute = get_dropdown (asset_dropdown);
      var Sub_Attribute = get_dropdown (sub_dropdown);
      var Answer = Customer_Name + Asset_Name + Asset_Type + Sub_System;

      document.getElementById("output1").innerHTML = Answer;
}

</script>

</head>

<body>
<form name = "agc_ira" method="get" action="" >
<fieldset>
  <legend>Assessment Data</legend>
  <table>
  <tr>
    <td>Customer Name:</td>
    <td><input type="text" name="customer_name"></td>
  </tr>
  <tr>
    <td>Asset Name:</td>
    <td><input type = "text" name="asset_name"></td>
  </tr>
  <tr>
    <td>Asset Attribute:</td>
    <td><select name="asset_dropdown">
          <option value="1">1</option>
          <option value="2">2</option>
          <option value="3">3</option>
        </select></td>
  </tr>
  <tr>
  <td>Sub-Attribute:</td>
  <td><select name="sub_dropdown">
        <option value="A">A</option>
        <option value="B">B</option>
        <option value="C">C</option>
      </select></td>
  </tr>
  </table>
 </fieldset>

 <br><input type="button" name="runmodel" value="Run" onclick="getval()"> 
 <br>
 <p id="output1"></p>

 </form>
 </body>
 </html>

```