[рони]

$(function () {
    function log(message, id) {
        id = "#" + id.replace("Name", "Id");
        $(id).val(message)
    }
    $("[id^='RegionName']").autocomplete({
        source: "/regions-for-admin",
        minLength: 3,
        select: function (event, ui) {
            log(ui.item.value, this.id)
        }
    })
});