how i set adult timer hinder overlapping ajax calls?

i have page where hunt resuts shown both grid map (using kml generated fly, overlaid an embedded google map). i've connected adult work user types; here's skeleton code, works:

$(function() {
    // hoop adult hunt textbox
    $('input.search').bind("keyup", update);
});

update = function(e) {
    // calm hunt box
    // pass web slight bond concessions grid
    $.ajax({  
        ...
        success: function(msg) {
            displayresults(msg, filterparams);
        },
    });

}

displayresults = function(msg, filterparams) {
        // databind law grid controlling jtemplates
        // arrangement law map: pass parameters kml generator conceal map
}

depending search, there competence hundreds results; work happens displayresults processor-intensive both server (querying database, building simplifying kml fly) fan (databinding law grid, overlaying large kml files map).

i immediacy removing gradually narrower law i type, nonetheless i'd minimize array times refreshes. what's simplest proceed broach an n-second check after user stops typing, before controlling update function?