How to auto delete emply lines in Word by using Access code?

I have a template in MS Word, I want to write Access code to fill up the empty fields where bookmarked in the template. But I encountered a prob:
In the template (see attachment), I put [bkmAddressLine1] to [bkmAddressLine5] in 5 different lines corresponding to tblClient.Address1 to tblClient.Address5 in Access. The addresses are varied in length. Some of them only filled up Address1 to Address3, leaving Address4 and Address5 empty. I don't want the empty lines, are there any ways to delete them?
Another problem is I can't write Null into Word using the code below, it'll return me an error "Invalid use of Null".Start Free Trial

1:

doc.Bookmarks("bkmAddressLine4").Range.Text = rs.Fields("Address4").Value