<com:TContent ID="Content"> <com:TTimeTriggeredCallback ID="Trigger" ActiveControl.CausesValidation="false" OnCallback="Page.onTriggerCallback" Interval="2" /> Count: <com:TActiveLabel ID="count" Text="0" /> <com:TTextBox ID="testBox" /> <com:TRequiredFieldValidator ControlToValidate="testBox" Display="Dynamic" ErrorMessage="Please insert a Text." /> <com:TCheckBox Text="Test2" Attributes.OnClick="console.log(this.checked)" AutoPostBack="True" /> </com:TContent>