In my "Total Days" column, I have the following formula and it works:

E4 is Date sent to Vendor

=DATEDIF(A3,TODAY(),"d")

now, I want to add to this formula, if possible, to say if a date is entered
into the second column, then just calculate "Date Sent" - "Date Returned" in
the same "Total Days" column...is this possible?? I manually entered the "1"

Date sent to Vendor Date Returned From Vendor Total Days
out to Vendor
4/22/2010 4
4/22/2010 4/23/2010 1
4/23/2010 3
4/23/2010 3
4/23/2010 3
4/23/2010 3
4/26/2010 0
4/26/2010 0