CORS Javascript

cors.js

window.onerror = function(errorMsg, file, lineNo, colNo, errStack) {
    "use strict";
    var msg = errorMsg ? errorMsg : "null"
    , stack = errStack ? errStack : "null, only Chrome/Chromium/Firefox based browsers support errorStack"
    , errFile = file ? file : "null"
    , errLineNo = lineNo ? lineNo : "null"
    , msgElem = document.getElementById("MSG")
    , stackElem = document.getElementById("STACK")
    , fileElem = document.getElementById("FILE")
    , lineElem = document.getElementById("LINE_NO")
    ;   
    if (msgElem && stackElem && fileElem && lineElem) {
      msgElem.innerHTML = msg;
      stackElem.innerHTML = stack;
      fileElem.innerHTML = errFile;
      lineElem.innerHTML = errLineNo;
    } else {
      alert("Unable to find div ids MSG, STACK, FILE, LINE_NO on page");
    }   
};

window.clickMe = function(e) {
    "use strict";
    if (e) {
      e.preventDefault();
    }   
    var l = "test";
    l.callme();
};