cument.msfullscreenElement && document.msfullscreenElement !== null) || (!document.mozFullScreen && !document.webkitIsFullScreen)) {
    if ((document.fullScreenElement !== undefined && document.fullScreenElement === null) || (document.msFullscreenElement !== undefined && document.msFullscreenElement === null) || (document.mozFullScreen !== undefined && !document.mozFullScreen) || (document.webkitIsFullScreen !== undefined && !document.webkitIsFullScreen)) {
        if (elem.requestFullScreen) {
           