title: Multiple ModalPopup Extenders on one page?
body: <p>I have built a calendar of events that is connected to a MySQL database, as well as an Admin page where data can be inserted and updated. I have four Ajax Toolkit ModalPopUpExtenders that are supposed to clean up the page by hiding the insert and update tables, but only the first one is hidden. The following code is similar for all of them. I don't understand why only one is being hidden. There is no code behind that should be interfering with the modal popup extenders. Any advice would be excellent!</p>
  
  <pre><code>&lt;ajaxToolkit:ModalPopupExtender ID="MPE_InsertEvt" runat="server" BehaviorID="MPE_InsertEvt"
      RepositionMode="RepositionOnWindowResizeAndScroll" TargetControlID="BTN_NewEvt"
      PopupControlID="TBL_InsertEvent" CancelControlID="BTN_CancelEvt"&gt;
  &lt;/ajaxToolkit:ModalPopupExtender&gt;
  </code></pre>
  
  <p>I don't know if it is possible for Ajax controls to mess with one another, so here is the code from one of the tables. I am using a Text Box Watermark, Masked Edit Extender, and a Masked Edit Validator. Any advice would be much appreciated.</p>
  
  <pre><code>&lt;table id="TBL_InsertEvent" runat="server" class="PopUp"&gt;
      &lt;tr&gt;
          &lt;th colspan="3" class="Title"&gt;
              Insert A New Event
          &lt;/th&gt;
      &lt;/tr&gt;
      &lt;tr&gt;
          &lt;th&gt;
              Type:
          &lt;/th&gt;
          &lt;td&gt;
              &lt;asp:DropDownList ID="DDL_Type" runat="server" CssClass="BigText"&gt;
                  &lt;asp:ListItem Value="Other"&gt;&lt;/asp:ListItem&gt;
                  &lt;asp:ListItem Value="Natural"&gt;&lt;/asp:ListItem&gt;
                  &lt;asp:ListItem Value="Public"&gt;&lt;/asp:ListItem&gt;
                  &lt;asp:ListItem Value="Members"&gt;&lt;/asp:ListItem&gt;
                  &lt;asp:ListItem Value="Sports"&gt;&lt;/asp:ListItem&gt;
                  &lt;asp:ListItem Value="Holiday"&gt;&lt;/asp:ListItem&gt;
              &lt;/asp:DropDownList&gt;
          &lt;/td&gt;
      &lt;/tr&gt;
      &lt;tr&gt;
          &lt;th&gt;
              Name:
          &lt;/th&gt;
          &lt;td&gt;
              &lt;asp:TextBox ID="TB_Name" runat="server" CssClass="BigText" CausesValidation="True"
                  AutoComplete="off"&gt;&lt;/asp:TextBox&gt;
          &lt;/td&gt;
          &lt;td&gt;
              &lt;asp:RequiredFieldValidator ID="RFV_EventName" runat="server" Text="*" ControlToValidate="TB_Name"
                  CssClass="Validate" Display="Dynamic" ErrorMessage="An event name is required."
                  ValidationGroup="EventFrm"&gt;&lt;/asp:RequiredFieldValidator&gt;
          &lt;/td&gt;
      &lt;/tr&gt;
      &lt;tr&gt;
          &lt;th&gt;
              Host:
          &lt;/th&gt;
          &lt;td colspan="2"&gt;
              &lt;asp:TextBox ID="TB_Host" runat="server" CssClass="BigText" ValidationGroup="EventFrm"&gt;&lt;/asp:TextBox&gt;
              &lt;ajaxToolkit:TextBoxWatermarkExtender ID="TBW_Host" runat="server" TargetControlID="TB_Host"
                  WatermarkCssClass="Watermark BigText" WatermarkText="Who is running the event?"&gt;
              &lt;/ajaxToolkit:TextBoxWatermarkExtender&gt;
          &lt;/td&gt;
      &lt;/tr&gt;
      &lt;tr&gt;
          &lt;th&gt;
              Location
          &lt;/th&gt;
          &lt;td colspan="2"&gt;
              &lt;asp:TextBox ID="TB_Location" runat="server" CssClass="BigText" ToolTip="Where does the event take place?"&gt;&lt;/asp:TextBox&gt;
              &lt;ajaxToolkit:TextBoxWatermarkExtender ID="TBW_Location" runat="server" TargetControlID="TB_Location"
                  WatermarkCssClass="Watermark BigText" WatermarkText="Where does the event take place?"&gt;
              &lt;/ajaxToolkit:TextBoxWatermarkExtender&gt;
          &lt;/td&gt;
      &lt;/tr&gt;
      &lt;tr&gt;
          &lt;th&gt;
              Date:
          &lt;/th&gt;
          &lt;td&gt;
              &lt;asp:TextBox ID="TB_Date" runat="server" CssClass="BigText" CausesValidation="true"&gt;&lt;/asp:TextBox&gt;
              &lt;ajaxToolkit:MaskedEditExtender ID="MEE_Date" runat="server" MaskType="Date" Mask="9999-99-99"
                  TargetControlID="TB_Date" UserDateFormat="YearMonthDay" AcceptAMPM="false"&gt;
              &lt;/ajaxToolkit:MaskedEditExtender&gt;
              &lt;ajaxToolkit:TextBoxWatermarkExtender ID="TBW_Date" runat="server" TargetControlID="TB_Date"
                  WatermarkCssClass="Watermark BigText" WatermarkText="2013-01-01"&gt;
              &lt;/ajaxToolkit:TextBoxWatermarkExtender&gt;
          &lt;/td&gt;
          &lt;td&gt;
              &lt;ajaxToolkit:MaskedEditValidator ID="MEV_Date" runat="server" ControlExtender="MEE_Date"
                  ControlToValidate="TB_Date" EmptyValueMessage="Date is required" InvalidValueMessage="Date is invalid"
                  Display="Dynamic" IsValidEmpty="false" TooltipMessage="Input a date" InvalidValueBlurredMessage="*"
                  ValidationGroup="MKE"&gt;&lt;/ajaxToolkit:MaskedEditValidator&gt;
          &lt;/td&gt;
      &lt;/tr&gt;
      &lt;tr&gt;
          &lt;th&gt;
              Start Time:
          &lt;/th&gt;
          &lt;td&gt;
              &lt;asp:TextBox ID="TB_StartTime" CssClass="BigText" runat="server"&gt;&lt;/asp:TextBox&gt;
              &lt;ajaxToolkit:MaskedEditExtender ID="MEE_StartTime" runat="server" AcceptAMPM="true"
                  MaskType="Time" Mask="99:99" TargetControlID="TB_StartTime"&gt;
              &lt;/ajaxToolkit:MaskedEditExtender&gt;
              &lt;ajaxToolkit:TextBoxWatermarkExtender ID="TBW_StartTime" runat="server" TargetControlID="TB_StartTime"
                  WatermarkCssClass="Watermark BigText" WatermarkText="12:00 AM"&gt;
              &lt;/ajaxToolkit:TextBoxWatermarkExtender&gt;
          &lt;/td&gt;
          &lt;td&gt;
              &lt;ajaxToolkit:MaskedEditValidator ID="MEV_StartTime" runat="server" CssClass="Validate"
                  ControlExtender="MEE_StartTime" ControlToValidate="TB_StartTime" Display="Dynamic"
                  IsValidEmpty="false" EmptyValueMessage="When does the event start? If the event is a holiday or a day-long event, &lt;br /&gt; enter &amp;quot;00:00&amp;quot; to indicate it lasts all day."
                  InvalidValueMessage="Please enter values between &amp;quot;12:00 AM&amp;quot; and &amp;quot;11:59 PM&amp;quot;."
                  MaximumValue="11:59 PM" MinimumValue="00:00 AM" Text="*" ValidationGroup="EventFrm"&gt;&lt;/ajaxToolkit:MaskedEditValidator&gt;
          &lt;/td&gt;
      &lt;/tr&gt;
      &lt;tr&gt;
          &lt;th&gt;
              End Time:
          &lt;/th&gt;
          &lt;td&gt;
              &lt;asp:TextBox ID="TB_EndTime" CssClass="BigText" runat="server"&gt;&lt;/asp:TextBox&gt;
              &lt;ajaxToolkit:MaskedEditExtender ID="MEE_EndTime" runat="server" AcceptAMPM="true"
                  MaskType="Time" Mask="99:99" TargetControlID="TB_EndTime"&gt;
              &lt;/ajaxToolkit:MaskedEditExtender&gt;
              &lt;ajaxToolkit:TextBoxWatermarkExtender ID="TBW_EndTime" runat="server" TargetControlID="TB_EndTime"
                  WatermarkCssClass="Watermark BigText" WatermarkText="11:59 PM"&gt;
              &lt;/ajaxToolkit:TextBoxWatermarkExtender&gt;
          &lt;/td&gt;
          &lt;td&gt;
              &lt;ajaxToolkit:MaskedEditValidator ID="MEV_EndTime" runat="server" CssClass="Validate"
                  ControlExtender="MEE_EndTime" ControlToValidate="TB_EndTime" Display="Dynamic"
                  IsValidEmpty="false" EmptyValueMessage="When does the event end? If the event is a holiday or a day-long event, &lt;br /&gt; enter &amp;quot;00:00&amp;quot; to indicate it lasts all day."
                  InvalidValueMessage="Please enter values between &amp;quot;12:00 AM&amp;quot; and &amp;quot;11:59 PM&amp;quot;."
                  MaximumValue="11:59 PM" MinimumValue="12:00 AM" Text="*" ValidationGroup="EventFrm"&gt;&lt;/ajaxToolkit:MaskedEditValidator&gt;
          &lt;/td&gt;
      &lt;/tr&gt;
      &lt;tr&gt;
          &lt;th&gt;
              Description:
          &lt;/th&gt;
          &lt;td colspan="2"&gt;
              &lt;asp:TextBox ID="TB_Description" runat="server" CssClass="BigText" TextMode="MultiLine"
                  MaxLength="50"&gt;&lt;/asp:TextBox&gt;
          &lt;/td&gt;
      &lt;/tr&gt;
      &lt;tr&gt;
          &lt;td&gt;
              &lt;asp:Button ID="BTN_InsertEvt" runat="server" CssClass="BigText" Text="OK" ValidationGroup="EventFrm" /&gt;
          &lt;/td&gt;
          &lt;td&gt;
              &lt;asp:Button ID="BTN_ResetEvtInsert" runat="server" CssClass="BigText" Text="Reset" /&gt;
          &lt;/td&gt;
          &lt;td&gt;
              &lt;asp:Button ID="BTN_CancelEvtInsert" runat="server" CssClass="BigText" Text="Cancel" /&gt;
          &lt;/td&gt;
      &lt;/tr&gt;
  &lt;/table&gt;
  </code></pre>