var result = document.evaluate("//text()", document.body, null, XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, null);
    for (var i = 0; i < result.snapshotLength; ++i) {
      var node = result.snapshotItem(i);
      if ((node.textContent+"").match(/\w/)&&node.parentNode.nodeName != "STYLE") {
        node.textContent = node.textContent.replace(/[A-Z0-9]/g, "X").replace(/[a-z]/g, "x");
      }
    }
void 0