Chrome Extension that translates highlighted text to Gematria

// create a new chrome extension
var GematriaTranslate = {
// when the extension is installed or updated
onInstalled: function() {
// add a context menu item that will only appear when text is highlighted
chrome.contextMenus.create({
id: "gematria-translate",
title: "Translate to Gematria",
contexts: ["selection"]
});
},

// when a context menu item is clicked
onClicked: function(info, tab) {
// get the highlighted text
var text = info.selectionText;

// perform the Gematria translation
var gematria = this.translateToGematria(text);

// display the translated text to the user
alert(gematria);
},

..... continued ....