Scenario: 

I have the following controls:

```
<telerik:RadComboBox ID="dd1" runat="server" ValidationGroup="g1" InitialValue="-1" />
<telerik:RadComboBox ID="dd2" runat="server" ValidationGroup="g1" InitialValue="-1" />
<asp:CompareValidator ID="cv" runat="server" ValidationGroup="g1" InitialValue="-1"
                    ControlToValidate="dd1" ControlToCompare="dd2" Operator="NotEqual" Text="error"
                    Type="String" />

```

I don't want the 2 dropDowns to have the same values, excluding "-1" which is the default value of any dropdown.

Can I achieve this using the compareValidator? or should i use javascript?

thanks in advance