Sub grid - Display a message if a row is allow to be deleted from a sub grid

Hi

I have a sub grid that I check to see if a row in the sub grid can be deleted. 

I made changes to the ribbon that would call a javascript function that will display the message.  I enable my rule on the DeleteSelectedRecord in the ribbon. That logic is working fine.

My problem that I am having is that the Delete Dialog is also appearing at the same time. 

I would like to know if there is a way to display the message without the delete dialog appearing.  However if the row can be deleted then show the Delete Dialog.