JavaScript Help Needed

Hello Friends
I need help on javascript.Let I am using this code below on my site-

<script type="text/javascript">
var a=28/13;
	document.write(a);
</script>

Code (markup):

The result printed on page is 2.1538461538461537

But I want to print only two digits after point so the desired result should be 2.15
How can I do it?

 

Try it

<script type="text/javascript">
function short_number(number){
  number = ""+number;
    point = number.indexOf(".");
    if(point!=-1){
        fpart = number.substring(0,point);
        spart = number.substring(point+1);
        if(spart.length>2){
            spart = spart.substring(0,2);
        }
        number = fpart+"."+spart;
    }else{
        number = number+".00";
    }

    return number;
}

var a=28/13;
	document.write(short_number(a));
</script>

Code (markup):

 

Its working well.Thank a lot.