submit form with delay while entering data into input field

I have a simple form that I need to submit automatically when text is entered.

I can use the onChange or onKeyUp without the best result.

HTML is:

  <form action="" id="fusionSearchForm" method="post">
    <input type="text" class="std_input" id="fusion_searchText" />
  </form>

And jQuery

jQuery("#fusionSearchForm").keyup(function() {
  this.submit();
});

This submits every time a character is entered. I much rather would have it so - there was a delay before submit so you can finish your typing - that focus stays on the input field ready to type after submit (if reload)

Any way to delay a form.submit() so the user can finish typing before form is submitted?

(UPDATE to code to a more "jQuery" kind of way to submit)

Br. Anders