title: Calculate on form change
body: <p>I am not that pro with javascript, so I am here for help. I want to dynamicly calculate a price on change of form elements... </p>
  
  <p>the HTML Structure:</p>
  
  <pre><code>&lt;div class="semOrder"&gt;
          &lt;h1&gt;Calculate price&lt;/h1&gt;
          &lt;form name="bestelling" id="bestelling" method="GET" action="/offerte-aanvragen/" style="margin-top:10px" novalidate="novalidate"&gt;
      &lt;input name="p" value="S2V1a2VudGVudCA1JiMyMTU7NSw1bQ==" hidden=""&gt;
      &lt;input name="c" value="TGVnZXJ0ZW50ZW4=" hidden=""&gt;
      &lt;select name="d" style="color:white;" class="valid"&gt;
          &lt;option value="0" selected=""&gt;Aantal dagen:&lt;/option&gt;
          &lt;option value="1"&gt;1 day&lt;/option&gt;
          &lt;option value="2"&gt;2 days&lt;/option&gt;
          &lt;option value="3"&gt;3 days&lt;/option&gt;
          &lt;option value="4"&gt;4 days&lt;/option&gt;
          &lt;option value="5"&gt;5 days&lt;/option&gt;
          &lt;option value="6"&gt;6 days&lt;/option&gt;
          &lt;option value="7"&gt;7 days&lt;/option&gt;
      &lt;/select&gt;&lt;br&gt;&lt;br&gt;
      &lt;p&gt;Aantal: &lt;input name="a" value="1" style="width:20px!important"&gt; tenten&lt;/p&gt;
      &lt;p&gt;Prijs: &lt;input id="priceContainer" value="24,95"&gt;&lt;/p&gt;
      &lt;input id="persoonShower" type="submit" value="offerte aanvragen"&gt;
  &lt;/form&gt;
  
      &lt;/div&gt;
  </code></pre>
  
  <p>Now I need it that when the field with name <code>d</code>or <code>a</code> is being changed it should calculate with <code>(d * a)+5</code> and then return the amount in <code>#priceContainer</code>... </p>
  
  <p>A jQuery approche is prefferd... </p>
  
  <p>Thanks in advance! </p>