ajaxToolkit中，Calendar的验证有Culture的问题，如果要用MM/dd/yyyy这种格式，参考下面的设置：
<%@ Page
Language="C#"
MasterPageFile="~/DefaultMaster.master"
AutoEventWireup="true"
Inherits="CommonPage"
Culture="en-US"
UICulture="en-US"
Title="MaskedEdit Sample"
Theme="SampleSiteTheme" %>
<%@ Register
Assembly="AjaxControlToolkit"
Namespace="AjaxControlToolkit"
TagPrefix="ajaxToolkit" %>
<%@ Import Namespace="System.Threading" %>
<asp:Content ContentPlaceHolderID="SampleContent" runat="Server">
<ajaxToolkit:ToolkitScriptManager runat="server" ID="ScriptManager1" EnableScriptGlobalization="true" EnableScriptLocalization="true" />
<div class="demoarea">
<div class="demoheading">MaskedEdit Demonstration</div>
<asp:TextBox ID="TextBox5" runat="server" Width="130px" style="text-align:justify" ValidationGroup="MKE" />
<asp:ImageButton ID="ImgBntCalc" runat="server" ImageUrl="~/images/Calendar_scheduleHS.png" CausesValidation="False" />
<ajaxToolkit:CalendarExtender ID="CalendarExtender1" PopupButtonID="ImgBntCalc" Enabled="True" runat="server" TargetControlID="TextBox5" Format="MM/dd/yyyy" />
<ajaxToolkit:MaskedEditExtender ID="MaskedEditExtender5" runat="server"
TargetControlID="TextBox5"
Mask="99/99/9999"
OnFocusCssClass="MaskedEditFocus"
OnInvalidCssClass="MaskedEditError"
MaskType="Date"
CultureAMPMPlaceholder=""
CultureCurrencySymbolPlaceholder="" CultureDateFormat=""
CultureDatePlaceholder="" CultureDecimalPlaceholder=""
CultureThousandsPlaceholder="" CultureTimePlaceholder=""
CultureName="en-US"/>
<ajaxToolkit:MaskedEditValidator ID="MaskedEditValidator1" runat="server"
ControlExtender="MaskedEditExtender5"
ControlToValidate="TextBox5"
EmptyValueMessage="Date is required"
InvalidValueMessage="Date is invalid"
Display="Dynamic"
TooltipMessage="Input a date"
EmptyValueBlurredText="*"
InvalidValueBlurredMessage="*"
ValidationExpression="^\d{2}/\d{2}/\d{4}$" IsValidEmpty="False"
ValidationGroup="MKE"/>
