Get amount and put into inputbox

JavaScript
21

The down side of that solution is that if you want to change the prices, you have to do it in 2 places - the html and javascript.

An easier to maintain solution will enable you to set the prices in only one location (either the js or html) and the second location gets the data it needs from the first location automatically.

22

I found a solution, thanks to Dominic H from Yahoo! Answers :slight_smile:

It’s simple but very effective and it works perfectly!

Here’s the entire code:


<!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">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Get amount and put into inputbox</title>
</head>

<body>

<form action="">

  <fieldset>
  
    <ul style="list-style:none;padding-left:0;">
      <li>Ice Cream:
        <select class="optionsIceCream" name="IceCream">
          <option value="IceCream01">Select Ice Cream</option>
          <option value="IceCream02">Solero Exotic (+$1.85)</option>
          <option value="IceCream03">Magnum Ecuador (+$4.85)</option>
          <option value="IceCream04">Cornetto Enigma (+$2.00)</option>
        </select>
      </li>
          
      <li>Coffee:
        <select class="optionsCoffee" name="Coffee">
          <option value="Coffee01">Select Coffee</option>
          <option value="Coffee02">Cup of Joe (+$0.99)</option>
          <option value="Coffee03">Cappuccino (+$2.49)</option>
          <option value="Coffee04">Latte Macchiato (+$2.99)</option>
        </select>
      </li>
          
      <li>Computers:
        <select class="optionsComputers" name="Computers">
          <option value="Computer01">Select Computer</option>
          <option value="Computer02">Dell Inspiron 620 (+$449.99)</option>
          <option value="Computer03">HP Pavilion dv7t (+$949.99)</option>
          <option value="Computer04">iMac 27-inch 3.1GHz (+$1,999.00)</option>
        </select>
      </li>
    </ul>
        
    Total: <input class="totalAmount" type="text" disabled="disabled" value="0.00" />
  
  </fieldset>

</form>

<script type="text/javascript">
    //<![CDATA[
        (function () {
            var selects = document.getElementsByTagName("select"),
                L = selects.length,
                i;
                
            for (i = 0; i < L; i++) {
                selects[i].setAttribute("onchange", "calcTotal();");
            }
        }());
        
        function calcTotal() {
            var icecream = [0.00, 1.85, 4.85, 2.00],
                coffee = [0.00, 0.99, 2.49, 2.99],
                computer = [0.00, 449.99, 949.99, 1999.00],
                total = document.getElementsByTagName("input")[0],
                select = document.getElementsByTagName("select");
                        
            total.value = (icecream[select[0].selectedIndex] +
                coffee[select[1].selectedIndex] + 
                computer[select[2].selectedIndex]).toFixed(2);
        }
    //]]>
</script>

</body>
</html>