How do I pass the contents of a textarea field to a java applet

<script>
  document.getElementById("mybutton").addEventListener("click", function() {
    document.getElementById("myapplet").myJavaMethod(
      document.getElementById("mytextarea").value);
  }, false);
</script>

<textarea id="mytextarea"></textarea>
<button id="mybutton">click me</button>
<applet id="myapplet" ...></applet>