michael@0: 
michael@0: function foo(x, y) {
michael@0:   for (var i = 0; i < x.length; i++) {
michael@0:     x[i];
michael@0:     if (i < 20)
michael@0:       y[i + 1] = 0;
michael@0:   }
michael@0: }
michael@0: 
michael@0: var q = Array(1,2,3,4,5);
michael@0: foo(q, []);