Chaining and queuing ajax requests using jquery deferred

I have a clunky ajax queue that uses setTimeout and a global flag:

var InProgress = false;

function SendAjax(TheParameters) {

  if (InProgress) {
     setTimeout(function () { SendAjax(TheParameters) } , 500) 
  }

  InProgress = true;

  $.ajax({
    ...
    data: TheParameters,
    complete: InProgress = false
  });
}

How can I rewrite this using a queuing mechanism so that the requests trigger one after the other in the order they're received?

Thanks.