<com:TContent ID="Content"> <com:TCheckBoxList ID="list1" AutoPostBack="true" ValidationGroup="group1" > <com:TListItem Text="Item 1" /> <com:TListItem Text="Item 2" /> <com:TListItem Text="Item 3" /> </com:TCheckBoxList> <com:TCustomValidator ID="validator1" ControlToValidate="list1" OnServerValidate="do_validate_1" ValidationGroup="group1" ErrorMessage="group1 error" /> <com:TRadioButtonList ID="list2" AutoPostBack="true" ValidationGroup="group2" > <com:TListItem Text="Item 1" /> <com:TListItem Text="Item 2" /> <com:TListItem Text="Item 3" /> </com:TRadioButtonList> <com:TCustomValidator ID="validator2" ControlToValidate="list2" OnServerValidate="do_validate_2" ValidationGroup="group2" ErrorMessage="group2 error" /> </com:TContent>