# Validation

You can use the built-in ASP.NET validation with **RadPanelBar**. The panel bar can trigger validation of other controls on the form when it performs a post-back to the server. Simply set the **CausesValidation** property to **True**.

By default, all validators on the Web page must be successful before the postback can occur. You can limit the controls that must be validated when the panel bar performs a post-back, while still allowing other controls on the Web page to be validated, by using **Validation Groups**. The validator controls have a **ValidationGroup** property. The panel bar also has a **ValidationGroup** property. The panel bar only causes validation by those validators whose **ValidationGroup** property matches the **ValidationGroup** property of the panel bar. The reason that the default behavior is for all validators to execute on post-back is because the default value of the **ValidationGroup** property on both **RadPanelBar** and validators is an empty string.