Prototype/index.js

$(document).ready(function () {
    FTPUI.handleLocalButtons();
    // the page will be updated to take user input (i.e host, port, username, password)
    var client = new FTPSession("ftp.mozilla.org", 21);
      client.login("", "").then(function (welcomeMsg) {
      client.listDir().then(function (listDir) {
        FTPUI.createRemoteDir(client, listDir);
        FTPUI.handleRemoteBackButton();
        FTPUI.handleDownload();
      }).catch(function (error) {
        // listDir error handling
        console.log(error);
      });
    }).catch(function (error) {
      console.log("Caught login error", error);
    });
});