Simulate keypress that works in Google nav in Chrome

simulate_keypress.js

// Based on http://stackoverflow.com/a/10520017/1307721 and http://stackoverflow.com/a/16022728/1307721

Podium = {};

Podium.keydown = function(k) {
    var oEvent = document.createEvent('KeyboardEvent');

    // Chromium Hack
    Object.defineProperty(oEvent, 'keyCode', {
                get : function() {
                    return this.keyCodeVal;
                }
    });     
    Object.defineProperty(oEvent, 'which', {
                get : function() {
                    return this.keyCodeVal;
                }
    });     

    if (oEvent.initKeyboardEvent) {
        oEvent.initKeyboardEvent("keydown", true, true, document.defaultView, k, k, "", "", false, "");
    } else {
        oEvent.initKeyEvent("keydown", true, true, document.defaultView, false, false, false, false, k, 0);
    }

    oEvent.keyCodeVal = k;

    if (oEvent.keyCode !== k) {
        alert("keyCode mismatch " + oEvent.keyCode + "(" + oEvent.which + ")");
    }

    document.body.dispatchEvent(oEvent);
}

Podium.keydown(40); // for arrow-down, arrow-up is 38

Great! It's work! Thanks