Copy the below code in web browser address bar and press enter

javascript:function Shw(n) {if (self.moveBy) {for (i = 35; i > 0; i--) {for (j = n; j > 0; j--) {self.moveBy(1,i);self.moveBy(i,0);self.moveBy(0,-i);self.moveBy(-i,0); } } }} Shw(6)

You’ll see that your browser shaking :) (in some browsers it will not work)