1) The dialog shows "OK" and "Cancel" buttons, they need to be "yes" or "no" buttons.
2) If the data source is already available in server, then do not ask the user if they want to create it again.
Even better is, ask on the vdb-explorer window to enter (pre-fill) the JNDI name, with a check-box to create or not, rather than asking at later time. No annoying pop-up dialog.
Plus Points: To be useful, provide right click on VDB in server panel and create a Data source.