Sending commands to youtube iframe.

sendCommandIframeYT.js

window.callPlayer = function (iframe, func, args) {
        var iframe = document.getElementById(iframe);
        var src = iframe.getAttribute('src');

        if (src && src.indexOf('youtube.com/embed') !== -1) {
            iframe.contentWindow.postMessage(JSON.stringify({
                'event': 'command',
                'func': func,
                'args': args || []
            }), '*');
        }
    };