var editor = null;
function initEditor() {
  editor = new HTMLArea("ta");
  editor.generate();
  return false;
}
function insertHTML() {
  var html = prompt("Voer HTML code in.");
  if (html){ editor.insertHTML(html); }
}
function highlight() {
  editor.surroundHTML('<span style="background-color: yellow">', '</span>');
}