Jquery autocomplete remote call - disable after a space

Jquery autocomplete remote call - disable after a space

Sometimes my autocomplete ajax takes too long and the response happens too late - is there anyway to close the autocomplete processing/drop down (ignore the results from the JSON) once a user enters a space character?

Thanks

I'm using: 
  
    
   
  1. 	$(function() {
		var cache = {},
			lastXhr;
		$( "#birds" ).autocomplete({
			minLength: 2,
			source: function( request, response ) {
				var term = request.term;
				if ( term in cache ) {
					response( cache[ term ] );
					return;
				}

				lastXhr = $.getJSON( "search.php", request, function( data, status, xhr ) {
					cache[ term ] = data;
					if ( xhr === lastXhr ) {
						response( data );
					}
				});
			}
		});
	});
    2.