keypress event dont working without document ready using sharepoint-hosted app with rest api

i am displaying data in an autocomplete , my input box dont get the value first time only second times so for example when typing A, it dont dislay but second time i type A it displays the value but i want to to display the value on keypress the first time and not second, i am using a sharepoint hosted app, and without document.ready it wont work at also, so how could i do to preventing to need to type 2 times to display value?

var hostweburl;
var appweburl;
$(document).ready(function () {
$("#subSiteTitle").keypress(function () {

            hostweburl = decodeURIComponent(getQueryStringParameter("SPHostUrl"));
            appweburl = decodeURIComponent(getQueryStringParameter("SPAppWebUrl"));
            var scriptbase = hostweburl + "/_layouts/15/";
            $.getScript(scriptbase + "SP.RequestExecutor.js", execCrossDomainRequest);
            function execCrossDomainRequest() {
                var executor = new SP.RequestExecutor(appweburl);
                var queryUrl = appweburl + "/_api/SP.AppContextSite(@target)/web/webs?$select=Title,Url,WebTemplate&$filter=WebTemplate ne 'APP'&@target='" + hostweburl + "'";

                executor.executeAsync(
                     {
                         url: queryUrl,
                         method: "GET",
                         headers: { "Accept": "application/json; odata=verbose" },
                         success: successHandler,
                         error: errorHandler
                     }
                         );
            }
            function successHandler(data) {
                $("#subSiteTitle").keypress(function () {
                    var jsonObject = JSON.parse(data.body);
                    var dataArr = $.makeArray(jsonObject.d.results);
                    var resultArr = $.map(dataArr, function (item) {

                        return { label: item.Title, value: item.Url };


                    });


                    $('#subSiteTitle').autocomplete({
                        source: resultArr,
                        select: function (event, ui) {
                            window.location.href = ui.item.value;
                        }
                    });

                }
        )
            }


            function errorHandler(data, errorCode, errorMessage) {
                document.getElementById("Error").innerText =
                    "Could not complete cross-domain call: " + errorMessage;
            }

            function getQueryStringParameter(paramToRetrieve) {
                var params =
                    document.URL.split("?")[1].split("&");
                var strParams = "";
                for (var i = 0; i < params.length; i = i + 1) {
                    var singleParam = params[i].split("=");
                    if (singleParam[0] == paramToRetrieve)
                        return singleParam[1];
                }
            }

})

});