<!doctype html>
<html>
<body>
    <script>
        function Point(xpos, ypos){
            this.x=xpos; 
            this.y=ypos; 
        }
        Point.prototype.getDistance=function(p){ 
            return Math.sqrt(this.x*this.x+this.y*this.y); 
        }
        var p1=new Point(10,20); 
        var d1=p1.getDistance();
        var p2=new Point(10,30);
        var d2=p2.getDistance();
        doucument.writeln(d1+"<br />");
        doucument.writeln(d2+"<br />");
    </script>
</body>
</html>