Legacy JSONP request maker. (Tested on > IE7, > Chrome21, > Firefox 17)

jsonp.legacy.js

  var $jsonp = (function () {
    var that = {};
    that.send = function (src, options) {
      var options = options || {},
        callback_name = options.callbackName || 'callback',
        on_success = options.onSuccess || function () {
          },
        on_timeout = options.onTimeout || function () {
          },
        timeout = options.timeout || 10;
      var timeout_trigger = window.setTimeout(function () {
        window[callback_name] = function () {
        };
        on_timeout();
      }, timeout * 1000);
      window[callback_name] = function (data) {
        window.clearTimeout(timeout_trigger);
        on_success(data);
      };
      var script = document.createElement('script');
      script.type = 'text/javascript';
      script.async = true;
      script.src = src;
      document.getElementsByTagName('head')[0].appendChild(script);
    };
    return that;
  })();