Anyone who had done a jquery Throttle function?

Anyone who had done a jquery Throttle function?

I make a function like this:
  1. function throttle(fn, delay) {  
  2.   var timer = null;  
  3.   return function () {  
  4.     var context = this, args = arguments;  
  5.     clearTimeout(timer);  
  6.     timer = setTimeout(function () {  
  7.       fn.apply(context, args);  
  8.     }, delay);  
  9.   };  
  10. }  
  11.   
  12. // so when you do this with jQuery, here is what you should do  
  13. $('input.username').keypress(throttle(function (event) {  
  14.   // do the Ajax request  
  15. }, 250));  
and i find a problem , if my request to the server have no response, what should i do then ?

I had wrote it in my blog  http://dev-tricks.com/throttle-function-in-javascript/ can anyone answer me?