I am relatively novice to javascript. I have written a simple counter program that starts count down from 10 till it reaches 1.

  <script type=text/javascript>

    function countDown(secs) {

        var element = document.getElementById(status);

        element.innerHTML = Please wait for +secs+ seconds;

        if(secs < 1) {

            clearTimeout(timer);

            element.innerHTML = '<h2>Countdown Complete!</h2>';

            element.innerHTML += '<a href=#>Click here now</a>';

        }

        secs--;

 --->       **var timer = setTimeout('countDown('secs')',1000);**

    }

    </script>

    <div id=status></div>

    <script type=text/javascript>countDown(10);</script>

Then I tried passing parameter as '+secs+' to the countDown function.

var timer = setTimeout('countDown('+secs+')',1000);

Above change works.

My question is why should I need to pass parameter as '+secs+' and NOT only 'secs' ?
What difference does it make?