Hi Louis

a formula can only affect the cell it is in .. ie you need to put the IF
formula in C1 if you want the formula to affect C1
you can get around this using VBA
or alternatively, you might like to check out using Data / Validation
click in C1 chose data / validation
choose custom
type
=B1<""
untick "ignore blank"
go to the error tab
write a message
click OK


--
Cheers
JulieD
check out www.hcts.net.au/tipsandtricks.htm
....well i'm working on it anyway
"Louis Pretorius (Johannesurg, RSA)" <Louis Pretorius (Johannesurg,
wrote in message
...
If I have a test in cell A1:
=if(TEST,let cell C1="MESSAGE1",let cell C1="MESSAGE2")

Note the cell with the if-condition in it is not the one that will contain
either MESSAGE1 or MESSAGE2

The reason is to let the user only enter a value in C1 once a value was
entered into B1. MESSAGE1 wold be something to the extent of "First select
the type in B1". This is to overwrite the user's entry into C1.