Fires on the client side when the editor loses input focus.
The LostFocus event handler receives an argument of the ASPxClientEventArgs type.
An editor's LostFocus event occurs on the client side before focus is moved from the editor to another control within the same page. This event can be handled to perform specific actions (for instance, to validate input from the user) when the editor loses focus.
Do not attempt to set focus from within the LostFocus event handler. Doing so can cause your application to stop responding.