I use EditItemTemplate and RadNumericTextBox.
How set default value to 100 into the RadNumericTextBox if the user does not fill in the value?
<telerik:GridTemplateColumn UniqueName="sortid" SortExpression="sortid" HeaderText="Sortering" EditFormHeaderTextFormat="" HeaderStyle-Width="100px">    <ItemTemplate>        <asp:Label ID="lblSortid" Text='<%# Eval("sortid") %>' runat="server" />    </ItemTemplate>    <EditItemTemplate>        <telerik:RadNumericTextBox ID="tbSortid" Width="100px" MaxLength="3" Text='<%# Bind("sortid") %>' EmptyMessage="Sortering (100)" ToolTip="Sortering" runat="server">            <NumberFormat DecimalDigits="0" GroupSeparator="" />        </telerik:RadNumericTextBox>        <asp:RequiredFieldValidator            ID="rfvSortid"            ControlToValidate="tbSortid"            Display="Dynamic"            ErrorMessage="Sortering (100)?"            ForeColor="#FF0000"            SetFocusOnError="true"            runat="server" />    </EditItemTemplate></telerik:GridTemplateColumn>