+ }
+
+ if (white_clock_ms === null || black_clock_ms === null) {
+ $("#whiteclock").empty();
+ $("#blackclock").empty();
+ return;
+ }
+
+ // If either player has ten minutes or less left, add the second counters.
+ var show_seconds = (white_clock_ms < 60 * 10 * 1000 || black_clock_ms < 60 * 10 * 1000);