jashkenas

// Handles JavaScript history management and callbacks. To use, register a
// regexp that matches the history hash with its corresponding callback.
window.HashHistory = {

  // The interval at which the window location is polled.
  URL_CHECK_INTERVAL : 500,

  // We need to use an iFrame to save history if we're in an old version of IE.
  USE_IFRAME : jQuery.browser.msie && jQuery.browser.version < 8,