I want to add to changes in this code

JavaScript
1

Hello, I am not an expert person in javascript. I have collected a javascript count down code from a website code from

another website. But I want to add some features in this code,

First: After the countdown is finished, a code something like 123456 will appear on the screen.

second: when it goes to zero and I switch the tab and come back again to the countdown tab, it again starts the negative

countdown.

Please give the Two solutions by editing the code thus I am not an expert, so please don’t say it in shortcut.

Code is given below

JS Bin $(document).ready(function() { // Create Countdown object var countdown = new Countdown({ seconds: 10 , onUpdateStatus:function(a){ $('#counter').text(a) /* insert code */ }, onCounterEnd: function() { /* insert code */ } }); 
        window.addEventListener('blur', function() {
           countdown.stop();
        });
      
        window.addEventListener('focus', function() {
           countdown.start();
        });
      
        // Start the countdown
        countdown.start();

    });

    function Countdown(a) {
        function d() {
            e(b);
            0 === b && (f(), g.stop());
            b--
        }
        var c, g = this,
            b = a.seconds,
            e = a.onUpdateStatus || function() {},
            f = a.onCounterEnd || function() {};
        this.start = function() {
            clearInterval(c);
            c = 0;
            c = setInterval(d, 1E3)
        };
        this.stop = function() {
            clearInterval(c)
        }
    }; 
</script>