如果输入的用户不在自动填充列表中，则添加用户

Question

I have an autocomplete that read mysql out * of customersName. On keyup or onchange doesnt matter wich one ,so , if user do not exist in mysql i need to display an new input (hided) and submit button to add new customer by name and email.

I need to know in wich direction to search , didnt find any info thanks.

Js:

$(function() {
    if ($('body').is('.PageType')) {
        $("#klantnaam").autocomplete({
            source: "zoekklant.php",
            minLength: 0,
            select: function(event, ui) {
                event.preventDefault();
                $("#klantnaam").val(ui.item.value);
                var str = ui.item.id;
                document.getElementById('doekprijs').textContent = str + " \u20ac";
            }
        });
    };
});