i have two modal popup extender control of ajax on same page.
one is showing registration for student and another for institutes.
when i remove all validation controls from send modal popup extender it works but i want validation control on my page
<asp:ModalPopupExtender ID="ModalPopupExtender1" runat="server" BackgroundCssClass="modalBackground"
PopupControlID="Panel1" TargetControlID="btnPopUp1" CancelControlID="btnClose1">
</asp:ModalPopupExtender>
<asp:Panel runat="server" ID="Panel1" CssClass="modalPopup" align="center" Style="display: none">
<center>
<div>
<asp:Label ID="Label2" runat="server" Text="Fileds marked with * are mandatory"></asp:Label><br />
<br />
<table>
<tr>
<td>
<asp:DropDownList ID="drpCourses" runat="server">
</asp:DropDownList>
</td>
<td>
<asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ErrorMessage="Field cannot be left blank"
SetFocusOnError="true" ControlToValidate="drpCourses" Text="*" ValidationGroup="grp1"
CssClass="ErrorMsg"></asp:RequiredFieldValidator>
</td>
</tr>
<tr>
<td>
<asp:TextBox runat="server" ID="txtName"></asp:TextBox><asp:TextBoxWatermarkExtender
ID="TextBoxWatermarkExtender2" runat="server" TargetControlID="txtName" WatermarkText="* Full Name ">
</asp:TextBoxWatermarkExtender>
</td>
<td>
<asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ErrorMessage="Field cannot be left blank"
SetFocusOnError="true" ControlToValidate="txtName" Text="*" ValidationGroup="grp1"
CssClass="ErrorMsg"></asp:RequiredFieldValidator>
</td>
</tr>
<tr>
<td>
<asp:TextBox runat="server" ID="txtEmail"></asp:TextBox><asp:TextBoxWatermarkExtender
ID="TextBoxWatermarkExtender3" runat="server" TargetControlID="txtEmail" WatermarkText="* E-mail ID ">
</asp:TextBoxWatermarkExtender>
</td>
<td>
<asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ErrorMessage="Field cannot be left blank"
SetFocusOnError="true" ControlToValidate="txtEmail" Text="*" ValidationGroup="grp1"
CssClass="ErrorMsg"></asp:RequiredFieldValidator>
<asp:RegularExpressionValidator ID="RegularExpressionValidator1" ControlToValidate="txtEmail"
Text="*" ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"
runat="server" ValidationGroup="grp1" CssClass="ErrorMsg" SetFocusOnError="true"
ErrorMessage="Invalid Email" />
</td>
</tr>
<tr>
<td>
<asp:TextBox runat="server" Text="+91" ReadOnly="true" Width="30px"></asp:TextBox>
<asp:TextBox runat="server" ID="txtMobile"></asp:TextBox><asp:TextBoxWatermarkExtender
ID="TextBoxWatermarkExtender4" runat="server" TargetControlID="txtMobile" WatermarkText="* Mobile number ">
</asp:TextBoxWatermarkExtender>
</td>
<td>
<asp:RequiredFieldValidator ID="RequiredFieldValidator4" runat="server" ErrorMessage="Field cannot be left blank"
SetFocusOnError="true" ControlToValidate="txtMobile" Text="*" ValidationGroup="grp1"
CssClass="ErrorMsg"></asp:RequiredFieldValidator>
</td>
</tr>
<tr>
<td>
<asp:TextBox runat="server" ID="txtCity"></asp:TextBox><asp:TextBoxWatermarkExtender
ID="TextBoxWatermarkExtender6" runat="server" TargetControlID="txtCity" WatermarkText="City ">
</asp:TextBoxWatermarkExtender>
</td>
</tr>
<tr>
<td>
<asp:TextBox runat="server" ID="txtState"></asp:TextBox><asp:TextBoxWatermarkExtender
ID="TextBoxWatermarkExtender5" runat="server" TargetControlID="txtState" WatermarkText="State ">
</asp:TextBoxWatermarkExtender>
</td>
</tr>
<tr>
<td>
<asp:TextBox runat="server" ID="txtComments" TextMode="MultiLine"></asp:TextBox><asp:TextBoxWatermarkExtender
ID="TextBoxWatermarkExtender7" runat="server" TargetControlID="txtComments" WatermarkText="Comments ">
</asp:TextBoxWatermarkExtender>
</td>
</tr>
<tr>
<td colspan="2">
<asp:ValidationSummary ID="ValidationSummary1" runat="server" ValidationGroup="grp1"
DisplayMode="BulletList" CssClass="ErrorMsg" />
</td>
</tr>
</table>
</div>
</center>
<asp:Button runat="server" ID="btnClose1" Text="Back" CssClass="btn_control" />
</asp:Panel>
<asp:ModalPopupExtender ID="ModalPopupExtender_2" runat="server" BackgroundCssClass="modalBackground"
PopupControlID="Panel2" TargetControlID="btnPopUp2" CancelControlID="btnClose2">
</asp:ModalPopupExtender>
<asp:Panel runat="server" ID="Panel2" CssClass="modalPopup" align="center" Style="display: none">
<center>
<div>
<asp:Label ID="Label1" runat="server" Text="Fileds marked with * are mandatory"></asp:Label><br />
<br />
<table>
<tr>
<td>
<asp:TextBox runat="server" ID="txtFullName"></asp:TextBox><asp:TextBoxWatermarkExtender
ID="TextBoxWatermarkExtender8" runat="server" TargetControlID="txtFullName" WatermarkText="* Full Name ">
</asp:TextBoxWatermarkExtender>
</td>
<td>
<asp:RequiredFieldValidator ID="RequiredFieldValidator6" runat="server" ErrorMessage="Field cannot be left blank"
SetFocusOnError="true" ControlToValidate="txtFullName" Text="*" ValidationGroup="grp2"
CssClass="ErrorMsg"></asp:RequiredFieldValidator>
</td>
</tr>
<tr>
<td>
<asp:TextBox runat="server" ID="txtEmailId"></asp:TextBox><asp:TextBoxWatermarkExtender
ID="TextBoxWatermarkExtender9" runat="server" TargetControlID="txtEmailId" WatermarkText="* E-mail ID ">
</asp:TextBoxWatermarkExtender>
</td>
<td>
<asp:RequiredFieldValidator ID="RequiredFieldValidator7" runat="server" ErrorMessage="Field cannot be left blank"
SetFocusOnError="true" ControlToValidate="txtEmailId" Text="*" ValidationGroup="grp2"
CssClass="ErrorMsg"></asp:RequiredFieldValidator>
<asp:RegularExpressionValidator ID="regEmail" ControlToValidate="txtEmailId" Text="*"
ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*" runat="server"
ValidationGroup="grp2" CssClass="ErrorMsg" SetFocusOnError="true" ErrorMessage="Invalid Email" />
</td>
</tr>
<tr>
<td>
<asp:TextBox ID="TextBox3" runat="server" Text="+91" ReadOnly="true" Width="30px"></asp:TextBox>
<asp:TextBox runat="server" ID="txtMobileNum"></asp:TextBox><asp:TextBoxWatermarkExtender
ID="TextBoxWatermarkExtender10" runat="server" TargetControlID="txtMobileNum"
WatermarkText="* Mobile number ">
</asp:TextBoxWatermarkExtender>
</td>
<td>
<asp:RequiredFieldValidator ID="RequiredFieldValidator8" runat="server" ErrorMessage="Field cannot be left blank"
SetFocusOnError="true" ControlToValidate="txtMobileNum" Text="*" ValidationGroup="grp2"
CssClass="ErrorMsg"></asp:RequiredFieldValidator>
</td>
</tr>
<tr>
<td>
<asp:TextBox runat="server" ID="txtCityName"></asp:TextBox><asp:TextBoxWatermarkExtender
ID="TextBoxWatermarkExtender11" runat="server" TargetControlID="txtCityName"
WatermarkText="City ">
</asp:TextBoxWatermarkExtender>
</td>
</tr>
<tr>
<td>
<asp:TextBox runat="server" ID="txtStateName"></asp:TextBox><asp:TextBoxWatermarkExtender
ID="TextBoxWatermarkExtender12" runat="server" TargetControlID="txtStateName"
WatermarkText="State ">
</asp:TextBoxWatermarkExtender>
</td>
</tr>
<tr>
<td>
<asp:TextBox runat="server" ID="txtPin"></asp:TextBox><asp:TextBoxWatermarkExtender
ID="TextBoxWatermarkExtender14" runat="server" TargetControlID="txtPin" WatermarkText="Pin Code ">
</asp:TextBoxWatermarkExtender>
</td>
</tr>
<tr>
<td>
<asp:TextBox runat="server" ID="txtComment" TextMode="MultiLine"></asp:TextBox><asp:TextBoxWatermarkExtender
ID="TextBoxWatermarkExtender13" runat="server" TargetControlID="txtComment" WatermarkText="Comments ">
</asp:TextBoxWatermarkExtender>
</td>
</tr>
<tr>
<td colspan="2">
<asp:ValidationSummary ID="ValidationSummary2" runat="server" ValidationGroup="grp2"
DisplayMode="BulletList" CssClass="ErrorMsg" />
</td>
</tr>
</table>
</div>
</center>
<asp:Button runat="server" ID="btnClose2" Text="Back" CssClass="btn_control" />
</asp:Panel>