Catch js errors when adding a script dynamically

http://stackoverflow.com/questions/20838067/catch-js-errors-when-adding-a-script-dynamically

by infous

JavaScript

window.onerror = alert;

try {
       var element = document.createElement("script");
        element.language = "javascript";
        element.type = "text/javascript";       
        element.defer = true;
    element.text = "functionff a() { alert(111); }";
        var head = document.getElementsByTagName('head')[0];
    head.appendChild(element);
} catch(err) {
  alert("error caught (that doesn't work)");
}