Alert uncaught errors when they happen

global-error.js

window.onerror = function(msg, url, line) {
   // You can view the information in an alert to see things working
   // like so:
   alert("Error: " + msg + "\nurl: " + url + "\nline #: " + line);

   // TODO: Report this error via ajax so you can keep track
   //       of what pages have JS issues

   var suppressErrorAlert = true;
   // If you return true, then error alerts (like in older versions of 
   // Internet Explorer) will be suppressed.
   return suppressErrorAlert;
};