XDocs document-v20: how to prevent duplication of values of alt + title attributes of img elements?

[Brolin Empey]

When I want the value of both the alt and title attributes of an img 
element in an XDocs document-v20 document to be equal, how can I prevent 
duplicating the value by copying and pasting it?  Can I declare the 
value of one attribute to use the value of another attribute?

--
A: Yes.
> Q: Are you sure?
>> A: Because it reverses the logical flow of conversation.
>>> Q: Why is top posting annoying?