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(function (window) {

  // Stores past URLs that failed to load. Used for a quick lookup
  // and because `onerror` is not triggered in some browsers
  // if the response is cached.
  var errors = {};

  // Check the existence of an image file at `url` by creating a
  // temporary Image element. The `success` callback is called
  // if the image loads correctly or the image is already complete.
  // The `failure` callback is called if the image fails to load
  // or has failed to load in the past.
  window.checkImage = function (url, success, failure) {
    var img = new Image(),    // the 
        loaded = false,
        errored = false;

    // Run only once, when `loaded` is false. If `success` is a
    // function, it is called with `img` as the context.
    img.onload = function () {
      if (loaded) {
        return;
      }

      loaded = true;

      if (success && success.call) {
        success.call(img);
      }
    };

    // Run only once, when `errored` is false. If `failure` is a
    // function, it is called with `img` as the context.
    img.onerror = function () {
      if (errored) {
        return;
      }

      errors[url] = errored = true;

      if (failure && failure.call) {
        failure.call(img);
      }
    };

    // If `url` is in the `errors` object, trigger the `onerror`
    // callback.
    if (errors[url]) {
      img.onerror.call(img);
      return;
    }
    
    // Set the img src to trigger loading
    img.src = url;

    // If the image is already complete (i.e. cached), trigger the
    // `onload` callback.
    if (img.complete) {
      img.onload.call(img);
    }
  };

})(this);

// Example Use
(function () {

  function success() {
    console.log("success: ", this.src);
  }

  function failure() {
    console.log("failure: ", this.src);
  }

  // this fails
  checkImage("http://www.google.com/", success, failure);

  // this succeeds
  checkImage("http://www.google.com/intl/en_com/images/srpr/logo3w.png", success, failure);

})();