это расширение календаря ajax extender или вы имели в виду элемент управления asp calendar? В любом случае, я попробовал и то, и другое в вашей описанной ситуации, и это работает. Попробуйте опубликовать какой-то код, который вы используете, чтобы мы могли увидеть, в чем проблема, и оказать дальнейшую помощь.
Редактировать: вот код, который я использовал от вашего. Я удалил пользовательский контроль, чтобы отладить страницу, и она, похоже, работала. Вот скриншот
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="test.aspx.cs" Inherits="web.test" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<style type="text/css">
.modalBackground
{
background-color: Gray;
filter: alpha(opacity=70);
opacity: 0.2;
}
.ob_show_panelsholder
{
border: 1px solid #736F6E;
}
.enterzipCalenderCompliant {
PADDING-RIGHT: 10px; FLOAT: left /*No display=inline*/
}
.ajax__calendar_container { z-index : 1000 ; }
</style>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="smtest" runat="server"></asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<asp:Panel ID="_pnlShowPersonalData" runat="server">
<table class="style1">
<tr>
<td>
<asp:Image ID="_imgCurrentPP" runat="server" Height="100px" Width="100px" />
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label3" runat="server" Text="First name :"></asp:Label>
</td>
<td>
<asp:Label ID="_lblFirstName" runat="server"></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label5" runat="server" Text="Last name :"></asp:Label>
</td>
<td>
<asp:Label ID="_lblLastName" runat="server"></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label7" runat="server" Text="BirthDate :"></asp:Label>
</td>
<td>
<asp:Label ID="_lblBirthDate" runat="server"></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label10" runat="server" Text="Mobile number :"></asp:Label>
</td>
<td>
<asp:Label ID="_lblMobileNumber" runat="server"></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label12" runat="server" Text="Location :"></asp:Label>
</td>
<td>
<asp:Label ID="_lblLocation" runat="server"></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label13" runat="server" Text="Gender :"></asp:Label>
</td>
<td>
<asp:Label ID="_lblGender" runat="server"></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Button ID="_btnEditPersonalData" runat="server" Text="Edit Profile" />
<ajaxToolkit:ModalPopupExtender ID="_btnEditPersonalData_ModalPopupExtender" runat="server" TargetControlID="_btnEditPersonalData" BackgroundCssClass="modalBackground" PopupControlID="_pnlEditPersonalData" CancelControlID="_btnCancel" />
</td>
</tr>
</table>
</asp:Panel>
<asp:Panel ID="_pnlEditPersonalData" runat="server">
<table>
<tr>
<td>
<asp:Label ID="_FirstName" runat="server" Text="First name :" ></asp:Label>
</td>
<td>
<asp:TextBox ID="_txtFirstName" runat="server"></asp:TextBox>
</td>
</tr>
<tr>
<td>
<asp:Label ID="_LastName" runat="server" Text="Last name :"></asp:Label>
</td>
<td>
<asp:TextBox ID="_txtLastName" runat="server"></asp:TextBox>
</td>
</tr>
<tr>
<td>
<asp:Label ID="_BirthDate" runat="server" Text="Birth date :"></asp:Label>
</td>
<td class="ajax__calendar_container">
<asp:TextBox ID="_txtBirthDate" runat="server"></asp:TextBox>
<ajaxtoolkit:MaskedEditExtender ID="_txtBirthDate_MaskedEditExtender" runat="server" Enabled="True"
TargetControlID="_txtBirthDate" MaskType="Date" ErrorTooltipEnabled="True" MessageValidatorTip="true"
Mask="99/99/9999">
</ajaxtoolkit:MaskedEditExtender>
<div>
<ajaxtoolkit:CalendarExtender ID="_txtBirthDate_CalendarExtender" runat="server" Enabled="True"
PopupButtonID="_btnCalendar" TargetControlID="_txtBirthDate">
</ajaxtoolkit:CalendarExtender>
</div>
<asp:ImageButton ID="_btnCalendar" runat="server" ImageUrl="~/Images/calendar_button_b.jpg" />
<%-- <img alt="Icon" src="~/Images/calendar_button_b.jpg" id="Image1" />--%>
</td>
</tr>
<tr>
<td>
<asp:Label ID="_ProfilePic" runat="server" Text="Profile picture :"></asp:Label>
</td>
<td>
<asp:FileUpload ID="FileUpload1" runat="server" />
<asp:Label ID="Label1" runat="server"></asp:Label>
<%-- <asp:RequiredFieldValidator ID="RequiredFieldValidator8" runat="server" ControlToValidate="FileUpload1"--%><%-- ErrorMessage="*" ValidationGroup="signup"></asp:RequiredFieldValidator>--%>
<asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server" ValidationExpression="^(([a-zA-Z]:)|(\\{2}\w+)\$?)(\\(\w[\w].*))(.png|.jpg)$"
ControlToValidate="FileUpload1" ErrorMessage="Please Select Png or Jpg File"
ValidationGroup="UploadFile"></asp:RegularExpressionValidator>
</td>
</tr>
<tr>
<td>
<asp:Label ID="_MobileNumber" runat="server" Text="Mobile number :"></asp:Label>
</td>
<td>
<asp:TextBox ID="_txtMobileNumber" runat="server"></asp:TextBox>
</td>
</tr>
<tr>
<td>
<asp:Label ID="_Password" runat="server" Text="Password :"></asp:Label>
</td>
<td>
<asp:TextBox ID="_txtPassword" runat="server"></asp:TextBox>
</td>
</tr>
</table>
<asp:UpdatePanel ID="UpdatePanel2" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<asp:Panel ID="_pnlLocation" runat="server">
<table width="21%">
<tr>
<td>
<asp:Label ID="_Country" runat="server" Text="Country :"></asp:Label>
</td>
<td>
</td>
</tr>
<tr>
<td>
<asp:Label ID="_Governet" runat="server" Text="Governet:"></asp:Label>
</td>
<td>
</td>
</tr>
<tr>
<td>
<asp:Label ID="_District" runat="server" Text="District :"></asp:Label>
</td>
<td>
</td>
</tr>
</table>
</asp:Panel>
</ContentTemplate>
<Triggers>
</Triggers>
</asp:UpdatePanel>
<table width="22%">
<tr>
<td>
<asp:Label ID="_Gender" runat="server" Text="Gender :"></asp:Label>
</td>
<td>
<asp:DropDownList ID="_ddlGender" runat="server">
<asp:ListItem Value="1">Male</asp:ListItem>
<asp:ListItem Value="2">Female</asp:ListItem>
</asp:DropDownList>
</td>
</tr>
<tr>
<td>
<asp:Button ID="_btnSaveChanges" runat="server" Text="Save changes"
ValidationGroup="signup" />
</td>
<td valign="bottom">
<asp:Button ID="_btnCancel" runat="server" Text="Cancel" />
</td>
</tr>
</table>
</asp:Panel>
</ContentTemplate>
</asp:UpdatePanel>
</form>
</body>
</html>