Creating One Chart from two Pivot tables combining X axis

I am trying to build a chart to show the progress of #
cumulative tasks planned by date versus # executed tasks
by date.

Source data looks like:

Task Plan Dt Exec Dt
A 08/12/2004 08/09/2004
B 08/12/2004 08/17/2004
C 08/14/2004
D 08/17/2004
E 08/17/2004

I want the X axis to start with the earliest plan or exec
date and end with the latest plan or exec date.

The first series should show the following points of
cumulative planned tasks:
08/12 - 2
08/13 - 2
08/14 - 3
08/15 - 3
08/16 - 3
08/17 - 5

The second series should plot on the same X-axis and show:

08/09 - 1
08/10 - 1
08/11 - 1
08/12 - 1
08/13 - 1
08/14 - 1
08/15 - 1
08/16 - 1
08/17 - 2

I've created different pivot tables and charted the data
from that point. I've tried different chart types, all to
no avail.

Please help!
Thanks,
Michelle