display textbox on clicking the checkbox inside telerik rad grid

I have a telerik radgrid where there are checkboxes with values. The values come from database. One of the value is OTHER. When the user checks the OTHER checkbox , a textbox should appear beside the OTHER value inside the grid.

How can I do this using javascript?

<telerik:RadGrid ID="grid_diag_group" runat="server"                       
                        Width="100%"                     
                        AutoGenerateColumns="false"
                        HeaderStyle-HorizontalAlign="Left" >
                        <MasterTableView>
                            <Columns>
                                <telerik:GridTemplateColumn UniqueName="TempCol1" HeaderText="Select" ReadOnly="true">
                                    <ItemTemplate>
                                        <asp:CheckBox ID="CheckBox1" runat="server" />
                                    </ItemTemplate>
                                    <EditItemTemplate>
                                        <asp:CheckBox ID="CheckBox2" runat="server" />
                                    </EditItemTemplate>
                                </telerik:GridTemplateColumn>
                                <telerik:GridBoundColumn DataField="diag_code" Display="false" Visible="true" AutoPostBackOnFilter="false" ItemStyle-HorizontalAlign="Left" CurrentFilterFunction="Contains" />                              
                                <telerik:GridBoundColumn DataField="diag_desc" UniqueName="diag_description" HeaderText="Diagnosis"
                                    AutoPostBackOnFilter="false" ItemStyle-HorizontalAlign="Left" />
                            </Columns>
                        </MasterTableView>
</telerik:RadGrid>

my UI is >>

[]  MALARIA
[]  T.B.
[]  GLYCOMA
[]  MEASELES
[]  FUNGAL INFECTION
[]  OTHERS

When user checks the OTHERS checkbox, textbox should appear beside "OTHERS" inside the grid. How can I do it?