Split Invoice?

[Aleksandr]

  I keep a daily record, using an Invoice (unposted), for each job I 
work on.  The invoice consists of my time and materials I purchase for 
the job.

In the current project I'm working on the customer wants me to split the 
daily record to account for 2 separate parts of the job.  Is there an 
easy way to make a copy of the Invoice (unposted) so that I can edit out 
the parts of the copy that apertain to a separate part of the entire 
project?