I've figured out how to insert a merge field in a bookmark as follows:

ActiveDocument.Bookmarks("Clientname").Range.Field s.Add ActiveDocument.Bookmarks("Clientname").Range, wdFieldMergeField, "FIRST_NAME"

What I want to do now is insert two merge fields (plus a space in between), e.g.:

FirstName LastName

How is this done? I've only been able to do it by using two bookmarks so far.

Thanks