Simple way to caching AJAX request result

simpleajaxcache.js

// define cache
var cache = {};

// ...
// within the AJAX callback
cache[url] = data;

// ...
// within callback that would set forth a request
if(cache[url]) {
    // Explicitly call the callback, passing it the cached page data
    return successCallback(cache[url]);
}
else {
    // do all of the AJAX request and callback
}