Update index.html

index.html

@@ -48,7 +48,7 @@
                         // check winner at cell i, j
                         var p = this.get(i, j);
                         if (p == 0) continue;
-                        for (let dxy of [[1, 0], [0, 1], [1, 1], [-1, 1]]) {
+                        for (let [dx, dy] of [[1, 0], [0, 1], [1, 1], [-1, 1]]) {
                             var count = 0;
                             for (let k = 1; k <= 4; k++) {
                                 const u = i + dx * k;