And to build on what Nick and Phil offerend, if you don't offer the 10%
discount until a second night (i.e. no discount for one night stands <g),
then assuming number of nights stay is in D4 with the rate in F4:

=IF(D41,D4*F4*.9,D4*F4)
You'll get D4*F4 for a one night stay, and
for anything longer than 1 night you'll get the discounted rate.

"dermot martin cleary" wrote:

If someone is staying in a hotel for two nights @ ‚¬80 per night.I go
=sum(d4*f4)enter and get ‚¬160 how do i then give a 10% discount ?.