Conditional data entry

[Beuwolf]

Hi all I have a database prob that i cant get my head around it goes a bit like this......

I want to be able to add differing ammounts to a worksheet (and invoice) dependat on the day that the work is carried out.....

if day one is a Fri then X ammount is displayed

if day one is a SAt the a differnt x ammount etc etc

Any ideas?

Marc