1 way.
Say your due date for payment is in A1. Select A1 and and then:-
Format|conditional format.
Select Formula is and paste this in
=AND(ISBLANK(B1),(A1-TODAY())>=3)
select a colour and click OK
3 days after payment is due the cell will turn the colour you select and it
will stay like that until you mark payment as recieved by entering something
in B1
I am gratefull to Mr.Mike and Mr.Pete that they respond to my answer,
Actually I am gold merchant and I always used to keep record of my stock,
suppose if I had given two necklace to one merchant so i want that excel
programme automatically prompt me after two day a pop up will come up
revealing that the payment is due so can i do this on Excel please guide me,
its really urgent