Code <script language ="javascript" type ="text/javascript"> function check(args) { var actual = args.length; //the actual length of the args if (actual != args.callee.length)//the expect number of the arguments thrownew Error("Wrong number args passed error!!"); } function f(x, y, z) { check(arguments); return x + y + z; } document.write("The sum is "+f(1,2)); </script>