json - jQuery set selected option from data on page load -

i have page uses jquery load option dropdown on page load. part works fine. want set selected option in dropdown baised on querystring if there 1 - , default if there not one. querystring being recovered fine can not setting of selected option work. in code below when stop @ "debugger" line , examine select0 undefined (after haveing been loaded successfully) if allow code keep running dropdown populated data ajax call. guessing why selected item not being set - can't figure out how resolve it.

    $(document).ready(function () {     $.ajax({            type: "post",            url: "mypage.aspx/mywebmethod",            contenttype: "application/json; charset=utf-8",            data: "{}",            datatype: "json",            success: function (states) {                var jsoncodes = json.parse(states.d);                (var in jsoncodes) {                    $("#select0").append(new option(jsoncodes[i].regionname, jsoncodes[i].region_id));                }                var first = geturlvars()["region"];                if (first) {                    $.fn.getinventory(1, 10, reg, 'rank', 'asc'); // if there querystring use                    $("#select0 option[text='" + reg + "']").get(0).selected = true;                }                else {                     debugger;                    var mytext = 'united states';                    $("#select0 option[text='" + mytext + "']").get(0).selected = true;                    $.fn.getinventory(1, 10, 'united states', 'rank', 'asc'); // if no query string default usa                          }            }        }); 

you're trying match text attribute not exist. cannot write:

$("#select0 option[text='" + mytext + "']").get(0).selected = true; 

you can use filter() instead:

$("#select0 option").filter(function() {     return $(this).text() == mytext; }).get(0).selected = true; 

or, taking more advantage of library:

$("#select0 option").filter(function() {     return $(this).text() == mytext; }).first().prop("selected", true);