title: How to disable all checkboxes on load, and enable them one by one as file is selected to upload?
body: <p>just need to disable the checkboxes on page load and enable them as the user selects a file to upload. For example, image is selected by user to upload for desktop so the sizes for desktop get enabled. Probably with javascript.</p>
  
  <pre><code>&lt;html&gt;
      &lt;head&gt;
          &lt;title&gt;Wallpaper Uploading Script&lt;/title&gt;
      &lt;style type="text/css"&gt;
          .formatting{
              font-family: Arial;
              font-size: .8em;
          }
          label{
              display: block;
              float: left;
              width: 150px;
              padding: 0 0px;
              margin: 0 0px 0;
              text-align: right;
          }
          form input, form textarea{
              margin: 2px 0 2px 2px;
          }
          .checkbox{
              text-align: left;
              display: block;
              padding: 2px;
          }
      &lt;/style&gt;
  
      &lt;script type="text/javascript"&gt;
  
      &lt;/script&gt;
      &lt;/head&gt;
  
      &lt;body class="formatting"&gt;
          &lt;p&gt;Select a file to Upload: &lt;/p&gt;
          &lt;form action="../php/get_uploaded_wall.php" method="POST" enctype="multipart/form-data"&gt;
              &lt;fieldset&gt;
                  &lt;label for="wall_name"&gt;Wall Name:&lt;/label&gt;
                  &lt;input type="text" name="wall_name" size="50" /&gt;&lt;br /&gt;
                  &lt;label for="thumbnail_path"&gt;Thumbnail path:&lt;/label&gt;
                  &lt;input type="file" name="thumbnail_path" size="100" /&gt;&lt;br /&gt;
                  &lt;label for="desktop_path"&gt;Desktop path:&lt;/label&gt;
                  &lt;input id="desktop_path" type="file" name="desktop_path" size="100" /&gt;&lt;br /&gt;
                  &lt;label for="phone_path"&gt;Phone path:&lt;/label&gt;
                  &lt;input type="file" name="phone_path" size="100" /&gt;&lt;br /&gt;
                  &lt;label for="tablet_path"&gt;Tablet path:&lt;/label&gt;
                  &lt;input type="file" name="tablet_path" size="100" /&gt;&lt;br /&gt;
                  &lt;label for="desktop_dimension_id"&gt;Desktop dimensions:&lt;/label&gt;
                  &lt;label class="checkbox" id="desktop_checkbox"&gt;
                      &lt;input type="checkbox" name="1366x768"&gt; 1366x768&lt;br /&gt;
                      &lt;input type="checkbox" name="1280x800"&gt; 1280x800&lt;br /&gt;
                      &lt;input type="checkbox" name="1920x1080"&gt; 1920x1080&lt;br /&gt;
                      &lt;span&gt;&lt;/span&gt;
                  &lt;/label&gt;
                  &lt;label for="phone_dimensions_id"&gt;Phone dimensions:&lt;/label&gt;
                  &lt;label class="checkbox" id="phone_checkbox"&gt;
                      &lt;input type="checkbox" name="640x960"&gt; 640x960&lt;br /&gt;
                      &lt;input type="checkbox" name="640x1136"&gt; 640x1136&lt;br /&gt;
                      &lt;input type="checkbox" name="960x720"&gt; 960x720&lt;br /&gt;
                  &lt;/label&gt;
                  &lt;label for="tablet_dimensions_id" id="tablet_checkbox"&gt;Tablet dimensions:&lt;/label&gt;
                  &lt;label class="checkbox"&gt;
                      &lt;input type="checkbox" name="1024x768"&gt; 1024x768&lt;br /&gt;
                      &lt;input type="checkbox" name="2048x1536"&gt; 2048x1536&lt;br /&gt;
                  &lt;/label&gt;
              &lt;/fieldset&gt;
              &lt;br /&gt;
              &lt;fieldset&gt;
                  &lt;input type="submit" value="Upload Wall" /&gt;
                  &lt;input type="reset" value="Clear" /&gt;
              &lt;/fieldset&gt;
          &lt;/form&gt;
      &lt;/body&gt;
      &lt;/html&gt;
  </code></pre>