Gridview Could not found control for modalpopupextender <p>I have a gridview with column "View" ID= "lnkViewContact". On click of this link signup modalpopupextender will be displayed. This popup is similar for all the rows. But when I am running it the error I am getting is "Could not found control lnkViewContact". How it can be resolved. one alternative is by using Onclick event on link click but I do not want to do a postback for opening the Popupextender. Below is my code:</p> <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false"> <div class="snippet-code"> <pre class="snippet-code-html lang-html prettyprint-override"><code> &lt;asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional"&gt; &lt;ContentTemplate&gt; &lt;asp:Panel ID="pnlNoData" runat="server" align="center" Visible="false" Style="height: 300px; width: auto;"&gt; &lt;h1 style="font-variant: normal; font-family: Times New Roman; font-size: 1.8em; margin-left: 15px; font-weight: lighter; color: Green; margin-top: 100px;"&gt; Refine your search.&lt;/h1&gt; &lt;h1 style="font-variant: normal; font-family: Times New Roman; font-size: 1.8em; margin-left: 15px; font-weight: lighter; color: Green; margin-left: 100px; margin-right: 100px;"&gt; Not finding suitable candidates. &lt;/h1&gt; &lt;cc1:ModalPopupExtender ID="mp3" runat="server" PopupControlID="pnlJobPost" BehaviorID="bvJobPost" TargetControlID="lnkPostJobReq" BackgroundCssClass="mBackground" CancelControlID="btnClose"&gt; &lt;/cc1:ModalPopupExtender&gt; &lt;asp:LinkButton ID="lnkPostJobSignUp" Text="Sign Up and Post Job" Font-Size="Medium" runat="server" OnClick="SignUp" Visible="false"&gt;&lt;/asp:LinkButton&gt; &lt;asp:LinkButton ID="lnkPostJobReq" Text="Post Job Requirement" Font-Size="Medium" runat="server"&gt;&lt;/asp:LinkButton&gt; &lt;/asp:Panel&gt; &lt;asp:GridView ID="grdSearchResult" runat="server" DataKeyNames="SeekerEmail_Id, Extension" OnRowDataBound="OnRowDataBound" AutoGenerateColumns="False" BorderWidth="1px" BackColor="White" CellPadding="5" BorderStyle="None" BorderColor="Gray" GridLines="Both" Width="100%"&gt; &lt;FooterStyle ForeColor="Black" BackColor="White"&gt;&lt;/FooterStyle&gt; &lt;PagerStyle ForeColor="Black" HorizontalAlign="Center" BackColor="White"&gt;&lt;/PagerStyle&gt; &lt;HeaderStyle ForeColor="White" Font-Bold="True" BackColor="Green"&gt;&lt;/HeaderStyle&gt; &lt;Columns&gt; &lt;asp:BoundField HeaderText="Job Skills" DataField="Primary_Skill" SortExpression="Primary_Skill" ItemStyle-Width="35%" ItemStyle-HorizontalAlign="Center" ItemStyle-Wrap="true" ItemStyle-CssClass="grdSearchResultbreakword"&gt;&lt;/asp:BoundField&gt; &lt;asp:BoundField HeaderText="Resume Title" DataField="Resume_Title" SortExpression="Resume_Title" ItemStyle-HorizontalAlign="Center" ItemStyle-Wrap="true" ItemStyle-Width="30%" ItemStyle-CssClass="grdSearchResultbreakword"&gt;&lt;/asp:BoundField&gt; &lt;asp:BoundField HeaderText="Exp (Years)" DataField="Experience" SortExpression="Experience" ItemStyle-HorizontalAlign="Center"&gt;&lt;/asp:BoundField&gt; &lt;asp:TemplateField HeaderText="Contact Details Email/Mobile" ItemStyle-HorizontalAlign="Center" ItemStyle-Width="12%"&gt; &lt;ItemTemplate&gt; &lt;asp:LinkButton ID="lnkViewContact" Text="View" runat="server"&gt;&lt;/asp:LinkButton&gt; &lt;/ItemTemplate&gt; &lt;/asp:TemplateField&gt; &lt;asp:TemplateField HeaderText="Contact Details Email/Mobile" ItemStyle-HorizontalAlign="Center" ItemStyle-Width="15%"&gt; &lt;ItemTemplate&gt; &lt;asp:Label ID="lblContact" ForeColor="DarkOrange" runat="server" Text='&lt;%# Eval("SeekerEmail_Id").ToString() +" / "+ Eval("Contact_Number").ToString() %&gt;' Style="word-wrap: normal; word-break: break-all; cursor: default;"&gt;&lt;/asp:Label&gt; &lt;/ItemTemplate&gt; &lt;/asp:TemplateField&gt; &lt;asp:TemplateField HeaderText="Download Resume" ItemStyle-HorizontalAlign="Center"&gt; &lt;ItemTemplate&gt; &lt;asp:LinkButton ID="lnkDown" Text="Download" runat="server" OnClick="SignUp"&gt;&lt;/asp:LinkButton&gt; &lt;/ItemTemplate&gt; &lt;/asp:TemplateField&gt; &lt;/Columns&gt; &lt;SelectedRowStyle ForeColor="White" Font-Bold="True" BackColor="#008A8C"&gt;&lt;/SelectedRowStyle&gt; &lt;RowStyle ForeColor="Black" BackColor="White"&gt;&lt;/RowStyle&gt; &lt;SortedAscendingCellStyle BackColor="#F1F1F1" /&gt; &lt;SortedAscendingHeaderStyle BackColor="#0000A9" /&gt; &lt;SortedDescendingCellStyle BackColor="#CAC9C9" /&gt; &lt;SortedDescendingHeaderStyle BackColor="#000065" /&gt; &lt;/asp:GridView&gt; &lt;asp:LinkButton ID="lnkFake" runat="server"&gt;&lt;/asp:LinkButton&gt; &lt;cc1:ModalPopupExtender ID="mp1" BehaviorID="behaviorIDmp1" runat="server" PopupControlID="Panl1" TargetControlID="lnkViewContact" CancelControlID="btnCancel" DropShadow="true" BackgroundCssClass="modalBackground"&gt; &lt;/cc1:ModalPopupExtender&gt; &lt;asp:Panel ID="Panl1" runat="server" CssClass="modalPopup" align="center" Style="display: none; height: 400px;" DefaultButton="btnRegister"&gt; &lt;%--&lt;h1 style="font-variant: normal; font-family: Comic Sans MS; font-size: 1.5em; font-weight: lighter; margin-top: 2px; margin-bottom: 2px; text-align: center; color: Blue;"&gt; SIGN UP&lt;/h1&gt;--%&gt; &lt;asp:Label ID="lblEmailId" runat="server" ForeColor="Black" Text="Email address" Style="font-weight: bold; display: block; text-align: left; margin-left: 45px; margin-top: 10px;"&gt;&lt;/asp:Label&gt; &lt;asp:TextBox ID="txtEmailAddress" runat="server" class="txtFirstName" MaxLength="100" name="email" TabIndex="3" value="" /&gt;&lt;br /&gt; &lt;asp:RequiredFieldValidator EnableClientScript="true" ID="reqEmailAdress" runat="server" ValidationGroup="modal" ControlToValidate="txtEmailAddress" ErrorMessage="Email Address Required" Display="Dynamic" Style="color: Red;" /&gt; &lt;asp:RegularExpressionValidator ID="regEmailAddress" runat="server" ErrorMessage="Not Valid Email ID" ValidationGroup="modal" Display="Dynamic" ControlToValidate="txtEmailAddress" ForeColor="Red" ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"&gt; &lt;/asp:RegularExpressionValidator&gt; &lt;asp:Label ID="lblContactNumber" runat="server" ForeColor="Black" Text="Contact Number(Don't prefix 0 or +91)" Style="font-weight: bold; display: block; text-align: left; margin-left: 45px;"&gt;&lt;/asp:Label&gt; &lt;asp:TextBox ID="txtContactNumber" runat="server" class="txtFirstName" MaxLength="15" name="contact" TabIndex="6" value="" /&gt;&lt;br /&gt; &lt;asp:RequiredFieldValidator EnableClientScript="true" ID="reqContactNumber" runat="server" ValidationGroup="modal" ControlToValidate="txtContactNumber" ErrorMessage="Contact Number Required" Display="Dynamic" Style="color: Red;" /&gt; &lt;asp:RegularExpressionValidator ID="regContactNumber" runat="server" ControlToValidate="txtContactNumber" ValidationGroup="modal" Text="Only 10 digit valid contact number is valid." ValidationExpression="[0-9]{10}" Style="color: Red;" Display="Dynamic"&gt;&lt;/asp:RegularExpressionValidator&gt; &lt;asp:Button ID="btnRegister" ValidationGroup="modal" class="btnempregsubmit" runat="server" Text="Save" OnClick="Register" CausesValidation="false" /&gt; &lt;br /&gt; &lt;asp:HyperLink ID="btnCancel" runat="server" Text="Cancel" CssClass="btnClosePopup"&gt;Close&lt;/asp:HyperLink&gt; &lt;/asp:Panel&gt; &lt;/ContentTemplate&gt; &lt;Triggers&gt; &lt;asp:AsyncPostBackTrigger ControlID="grdSearchResult" /&gt; &lt;asp:AsyncPostBackTrigger ControlID="btnRegister" /&gt; &lt;/Triggers&gt; &lt;/asp:UpdatePanel&gt;</code></pre> </div> </div> </p>