Validating dropdownlist inside gridview control
<p>for testing i have tried customvalidation</p>

<pre><code>function ClientValidate(sender, args) { 
       //return false for testing...
       args.IsValid = false;

    }

 &lt;asp:CustomValidator runat="server" ID="CustomValidator1" ControlToValidate="ddldetail"
                        Text="Please select" ValidateEmptyText="true"    
                        ClientValidationFunction="ClientValidate"  
                        Display="Dynamic"&gt;     
                    &lt;/asp:CustomValidator&gt;
</code></pre>

<p>edit: here is what i exaclty wants to happen:</p>

<p><img src="http://i.stack.imgur.com/L2lrf.png" alt="enter image description here"></p>

<p>how to validate a dropdownlist and i have done this zillion times but what i am doing wrong here? any second pair of eye might spot it? i am trying to validate the dropdownlist if the user have not select any help?</p>

<pre><code>&lt;asp:Button ID="btn" runat="server" Text="Submit" OnClick="btn_Click"  CausesValidation="true"/&gt;

&lt;asp:GridView ID="GVInputMapping" runat="server" AutoGenerateColumns="False" DataKeyNames="Id"
                     EnableModelValidation="True" onrowdatabound="GVInputMapping_RowDataBound"&gt;
                    &lt;Columns&gt;
                        &lt;asp:BoundField DataField="Name" ControlStyle-Width="250px" HeaderText="Name" SortExpression="Name" /&gt;
                        &lt;asp:TemplateField&gt;
                            &lt;ItemTemplate&gt;
                        &lt;asp:DropDownList runat="server" ID="ddldetail"&gt;
                        &lt;asp:ListItem Selected="True" Value="0"&gt;Select me&lt;/asp:ListItem&gt;
                        &lt;asp:ListItem Value="1"&gt;abc&lt;/asp:ListItem&gt;
                        &lt;asp:ListItem Value="2"&gt;GHt&lt;/asp:ListItem&gt;
                    &lt;/asp:DropDownList&gt;
    &lt;asp:RequiredFieldValidator ID="requiredDDL" runat="server" 
                        ControlToValidate="ddldetail" ErrorMessage="Please select" InitialValue="Select me"  Display="Dynamic"&gt;&lt;/asp:RequiredFieldValidator&gt;

                            &lt;/ItemTemplate&gt;
                        &lt;/asp:TemplateField&gt;
                    &lt;/Columns&gt;
                &lt;/asp:GridView&gt;
</code></pre>
