Select event does not work in autocomplete in jquery

<pre lang="Javascript">
function SearchText() {

            $('#<%=txtPinCode2.ClientID%>').autocomplete({
                minChars: 1,
                width: 6,                
                source: function (request, response) {
                    $.ajax({
                        type: "POST",
                        contentType: "application/json; charset=utf-8",
                        url: "scm/BranchSearch.ashx?act=bnkb&BankCode=" + $('#<%=ddlBank.ClientID %> :selected').val() + "&PinCode=" + $('#<%=txtPinCode2.ClientID%>').val(),
                        data: "{}",
                        dataType: "json",
                        success: function (data) {
                            mydata = new Array();
                            for (var i = 0; i < data.length; i++) {
                                mydata.push({
                                    label: data[i].BankBranchName,
                                    value: data[i].BanckBranchCode
                                });

                            }  //end of for loop

                            //setup the search to search the label and the description
                            var matcher = new RegExp($.ui.autocomplete.escapeRegex(request.term), "i");
                            response($.grep(mydata, function (arrItem) {                               
                                return matcher.test(arrItem.label);
                            }));

                        },
                        select: function (e,ui) {
                            alert(ui.item.label)
                                                   
                        },                        
                        error: function (result) {
                            alert("No Match");
                        }
                    });
                }

            });
        }