I am trying to convert all the classic controls to the new ones and while converting the webdatechooser to webdatepicker, I ran into an issue. I can select the dates in webdatepicker the first time but after that the dropdown does not opne at all. Also I have the webdatepicker inside and asyncrefreshpanel.Please help

<igeditor:WebDatePicker ID="FromDateChooser" BorderWidth="1px"  ClientIDMode="Static"

           runat="server" NullDateLabel=" " Value="<%#DateTime.Now - TimeSpan.FromDays(365)%>"

           DropDownCalendarID="WebMonthCalendar1"

           ShowMonthDropDown="False" ShowYearDropDown="False">

            <ClientSideEvents ValueChanging="set_str_date" />

         </igeditor:WebDatePicker>

           <igeditor:WebMonthCalendar  ID="WebMonthCalendar1" runat="server" Height="150px" TitleFormat="MonthAndYear"

               ShowNextPrevMonth="true" ShowFooter="False"  NextPrevFormat="ShortMonth" ShowMonthDropDown="False" ShowYearDropDown="False">

                </igeditor:WebMonthCalendar>

<igeditor:WebDatePicker ID="ToDateChooser" BorderWidth="1px" runat="server" NullDateLabel=" " ClientIDMode="Static"

        DropDownCalendarID="WebMonthCalendar2"

           ShowMonthDropDown="False" ShowYearDropDown="False">

<%--            <AutoPostBackFlags ValueChanged="On" />--%>

<ClientSideEvents ValueChanging="set_end_date" />

                      </igeditor:WebDatePicker>

           <igeditor:WebMonthCalendar  ID="WebMonthCalendar2" runat="server"  TitleFormat="MonthAndYear" Height="150px"

                ShowNextPrevMonth="true" ShowFooter="False"  NextPrevFormat="ShortMonth" ShowMonthDropDown="False" ShowYearDropDown="False">

<%--                 <AutoPostBackFlags SelectionChanged="On" />--%>

           </igeditor:WebMonthCalendar>

<script type="text/javascript">

function set_str_date(sender, args)

    {

if ($find("<%= FromDateChooser.ClientID %>").get_value() != "" &&

                $find("<%= ToDateChooser.ClientID %>").get_value() < args.get_value())

        {

            args.set_cancel(true);

        }

    }

function set_end_date(sender, args)

    {

if ($find("<%= ToDateChooser.ClientID %>").get_value() != "" &&

                $find("<%= FromDateChooser.ClientID %>").get_value() > args.get_value())

        {

            args.set_cancel(true);

        }

    } 

</script>

Please help..whats going wrong?its  urgent