mobile.js

  // This is a port of the prototype.js PeriodcialExecuter
  // This should be framework independent
  // Valuable if you like to/have to program in jQuery
function PeriodicalExecuter(callback, frequency) {
  this.callback = callback;
  this.frequency = frequency;
  this.currentlyExecuting = false;
  this.registerCallback();
}

PeriodicalExecuter.prototype = {
  registerCallback: function() {
    var me = this;
    this.timer = setInterval(function() { me.onTimerEvent() }, this.frequency * 1000);
  },

  execute: function() {
    this.callback(this);
  },

  stop: function() {
    if (!this.timer) return;
    clearInterval(this.timer);
    this.timer = null;
  },

  onTimerEvent: function() {
    if (!this.currentlyExecuting) {
      try {
        this.currentlyExecuting = true;
        this.execute();
      } finally {
        this.currentlyExecuting = false;
      }
    }
  }
};