On: The (JavaScript) Question I Bombed In An Interview With a Y Combinator Startup

[dmbass]

Capture the timeoutId in a closure.

  $(document).ready((function() {
    $('input').keypress((function() {
        var timeoutId = null;

        return function() {
            window.clearTimeout(timeoutId);
            timeoutId = window.setTimeout(function() {
                $.ajax({ /* ... * /});
            }, 200);
        };
    })());
  });

  // NB: this solution only works if there is one input.
  // If there are more than one, you need to create a new closure for each one.