<com:TContent ID="Content"> <com:TActivePanel ID="activePanelTest" > <!-- RELOAD --> nbReload : <com:TLabel ID="counter" Text="0" /> <com:TActiveLinkButton ID="reloadButton" OnCallback="Reload" > Reload </com:TActiveLinkButton> <br/> <!-- TEST --> <com:TTextBox ID="TextBox" /> <com:TActiveLinkButton ID="button1" OnCallback="Valid" ValidationGroup="v1" > Valid </com:TActiveLinkButton> <com:TRequiredFieldValidator ID="validator1" ValidationGroup="v1" ControlToValidate="TextBox" Text="ERROR, input 'TextBox' is empty" /> <!-- RESULTS --> <div style="border:1px solid red"> <com:TActiveLabel ID="Results" /> </div> </com:TActivePanel> BUG : click on 'Reload' with no text in the TextBox at anytime, and then, clicking on 'Valid' won't work... </com:TContent>