VS 2008 Fill Combobox Of Gridview

Code:
<asp:GridView ID="Grdview1" runat="server"
AutoGenerateColumns="False"
AllowPaging ="false" Width="100%"
>
<Columns>
<asp:TemplateField HeaderText="Cities">
<ItemTemplate >
<asp:DropDownList ID="cmb1" runat="server" >
<asp:ListItem Value="--Select--" Text="--Select--"></asp:ListItem>
<asp:ListItem Value="Faridabad" Text="Faridabad"></asp:ListItem>
<asp:ListItem Value="Delhi" Text="Delhi"></asp:ListItem>
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Addresses">
<ItemTemplate >
<asp:DropDownList ID="cmb2" runat="server" >
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>

I have two comboxes in GridView named cmb1 & cmb2. On selection Changed of cmb1,I want that cmb2 items to be fill from the database.