Timestamp and user stamp last update on a google sheet

gsheet-edit-stamp.js

function timestampIt(){
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var sheet = ss.getSheets()[0]; // this will assign the first sheet
  var cell = sheet.getRange('A1');
  var d = new Date();
  d.setHours(d.getHours() +1);
  var user = Session.getActiveUser().getUserLoginId();
  user = String(user);
  user = user.replace('@gmail.com', '');
  cell.setValue('Last updated: ' + d.toLocaleString() + ' by ' + user);
}

Thanks , But the user ID will not print in cell , I must run the script in script editor to print user ID in sheet . strange