popup.html

<!DOCTYPE html>
  <html>
    <head>
      <style>
        button {
          height: 35px;
          width: 35px;
          outline: none;
        }
        .icon {
          width: 28px;
          margin: -10px;

        }
      </style>
    </head>
    <body>
      <button id="pullText"><img title="suck up text" alt="suck up text" class="icon text_in" src="images/text_in_s.png"></button>
      <button id="setText"><img title="swap out text" alt="swap out text" class="icon text_out" src="images/text_out_s.png"></button>
      <button id="pullImg"><img title="suck up images" alt="suck up images" class="icon img_in" src="images/img_in_s.png"></button>
      <button id="setImg"><img title="swap out images" alt="swap out images" class="icon img_out" src="images/img_out_s.png"></button>
      <script src="popup.js"></script>
    </body>
  </html>