function detectDevTools() {
    document.addEventListener("keydown", function (event) {
        if (event.key === "F12" || (event.ctrlKey && event.shiftKey && (event.key === "I" || event.key === "J" || event.key === "C")) || (event.ctrlKey && event.key === "U")) {
            event.preventDefault();
            window.open('/404', '_self').close();
        }
    });
    document.addEventListener("contextmenu", function (event) {
        event.preventDefault();
    });
    !function () {
        function detectDevTool(allow) {
            if (isNaN(+allow)) allow = 100;
            var start = +new Date();
            debugger;
            var end = +new Date();
            if (isNaN(start) || isNaN(end) || end - start > allow) {
                window.open('/404', '_self').close();
            }
        }
        if (window.attachEvent) {
            if (document.readyState === "complete" || document.readyState === "interactive") {
                detectDevTool();
                window.attachEvent('onresize', detectDevTool);
                window.attachEvent('onmousemove', detectDevTool);
                window.attachEvent('onfocus', detectDevTool);
                window.attachEvent('onblur', detectDevTool);
            } else {
                setTimeout(argument.callee, 0);
            }
        } else {
            window.addEventListener('load', detectDevTool);
            window.addEventListener('resize', detectDevTool);
            window.addEventListener('mousemove', detectDevTool);
            window.addEventListener('focus', detectDevTool);
            window.addEventListener('blur', detectDevTool);
        }
    }();

}