+/**
+ * @param {number} num_viewers
+ */
+var update_num_viewers = function(num_viewers) {
+ if (num_viewers === null) {
+ $("#numviewers").text("");
+ } else if (num_viewers == 1) {
+ $("#numviewers").text("You are the only current viewer");
+ } else {
+ $("#numviewers").text(num_viewers + " current viewers");
+ }