jquery validation plugin highlight and unhighlight not working

jquery validation plugin highlight and unhighlight not working

hi all,
I am using J-Query Validation plugin 1.5.2.I  want to set control class to error css.But want to remove that class when i call validator.resetForm().But its not working..i dnt knw where i am wrong

This is my Validation script add on client side

$(document).ready(function () {
            jQuery.validator.addMethod("GenralText", function (value, element) {
                var RE_SSN = /^[a-zA-Z0-9-,.()\/ ]*$/;
                if (value.length > 0) {
                    if (RE_SSN.test(value)) {
                        return true;
                    }
                    else {
                        return false;
                    }
                }
                else { return true; }
            });
        });

        $(function () {
          $("#form1").validate({
                rules: {
                    txtConsignmentNumber: { required: true, GenralText: true },
                    ChkTeaConType: { required: function (element) { return (($("input[id='chkBulkTea']:checked").val() == undefined) || ($("input[id='chkPackagedTea']:checked").val() == undefined)) } }
                },
                messages: {
                    txtConsignmentNumber: { required: "*", GenralText: "*" },
                    ChkTeaConType: { required: "*" }
                },
                errorPlacement: function (error, element) {
                    error.appendTo(element.parent("td"));
                },
                 highlight: function (element, errorClass) {
                         var id = element.id;
                    $("#" + id).addClass(errorClass);
                    },
                    unhighlight: function (element, errorClass) {
                         var id = element.id;
                    $("#" + id).removeClass(errorClass);
                    },
                errorClass: "invalid"
            });
            $('select[id$=<%=ddlPort.ddlClientID %>]').rules('add', {
                required: function () { return (document.getElementById('<%=ddlPort.ddlClientID %>').value == '') },
                messages: { required: '*' }
            });

            $('select[id$=<%=ddlCountry.ddlClientID %>]').rules('add', {
                required: function () { return (document.getElementById('<%=ddlCountry.ddlClientID %>').value == '') },
                messages: { required: '*' }
            });
            $('select[id$=<%=ddlTTAMaster.ddlClientID %>]').rules('add', {
                required: function () { return (document.getElementById('<%=ddlTTAMaster.ddlClientID %>').value == '') },
                messages: { required: '*' }
            });
            $('select[id$=<%=ddlOrigin.ddlClientID %>]').rules('add', {
                required: function () { return (document.getElementById('<%=ddlOrigin.ddlClientID %>').value == '') },
                messages: { required: '*' }
            });
            $('select[id$=<%=ddlBasePRice.ClientID %>]').rules('add', {
                required: function () { return (document.getElementById('<%=ddlBasePRice.ClientID %>').value == '') },
                messages: { required: '*' }
            });

            $('select[id$=<%=ddlwarehouse.ddlClientID %>]').rules('add', {
                required: function () { return (document.getElementById('<%=ddlwarehouse.ddlClientID %>').value == '') },
                messages: { required: '*' }
            });
            $('input[id$=<%=txtExportDate.ClientID %>]').rules('add', {
                required: function () { return !(DayDiffToCurret($("#<%=txtExportDate.ClientID %>").val(), $("#<%=hfMinDays.ClientID %>").val())) },
                messages: { required: '*' }
            });
            $('textarea[id$=<%=txtRemark.ClientID %>]').rules('add', {
                required: function (element) { return !(($("input[id='chkLotBlwBP']:checked").val() == undefined)) },
                maxlength: 100,
                messages: { required: '*', maxlength: '*' }
            });
            $("#flex1").click(function () {
                ShowDetails($('.trSelected'));
            });
            isRowSelected = true;

        });

My CSs is
.invalid
{
    color: #000000;
    background-color: #AAFFEA;
}

please let me know where i am worng...