System.Web.UI.WebControls.ListItemCollection must have items of type 'System.Web.UI.WebControls.ListItem'. 'asp:RequiredFieldValidator'

Hi Akash,

You will have to format the page so that it appears to the right of the listbox outside of the listbox tag. You can accomplish this by using css layout or by rendering it as a two column, single row table like below.

From

<asp:RadioButtonList ID="rbAnswer" runat="server">
    <asp:ListItem Text="Not Yet Answered" Value="Not Yet Answered" Selected="True"></asp:ListItem>
    <asp:ListItem Text="No Information" Value="No Information"></asp:ListItem>
    <asp:ListItem Text="Yes, Will Reply Now" Value="Will Reply Now"></asp:ListItem>
    <asp:ListItem Text="Yes, Will Send Later" Value="Will Send Later"></asp:ListItem>
    <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ErrorMessage="RequiredFieldValidator"
        ControlToValidate="rbAnswer">
    </asp:RequiredFieldValidator>
</asp:RadioButtonList>

To

<table>
    <tr>
        <td>
            <asp:RadioButtonList ID="rbAnswer" runat="server">
                <asp:ListItem Text="Not Yet Answered" Value="Not Yet Answered" Selected="True"></asp:ListItem>
                <asp:ListItem Text="No Information" Value="No Information"></asp:ListItem>
                <asp:ListItem Text="Yes, Will Reply Now" Value="Will Reply Now"></asp:ListItem>
                <asp:ListItem Text="Yes, Will Send Later" Value="Will Send Later"></asp:ListItem>
            </asp:RadioButtonList>
        </td>
        <td>
            <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ErrorMessage="RequiredFieldValidator"
                ControlToValidate="rbAnswer"></asp:RequiredFieldValidator>
        </td>
    </tr>
</table>