Copying formula to the whole column

Hi
I have a sheet using the formula =IF(ISERROR(MATCH(C539,$T$2:$T$667,0)),"record needed","record not needed") on column F. It matches the value entered on C column with a product list on T column and if the name matches it says record needed else record not needed. I don't know how it happened, but previously there was nothing visible on F column, but as soon as i enter a name on C column, it would flash either of the two options. Now that is not working. I have to maually copy formula for a list of cells before anything is entered in C column. As many users are using the sheet, i want to know if it is possible to copy this formula to the whole F column and then make it invisible somehow so nothing is visible untill a name is entered on C column. It then should flash `record needed' or `record not needed' depending on whether the corresponding C value matches the list on T column.
Also, is it possible that if i make any changes (addition or deletion) to the list on T column, it automatically incorporates the change in the formula.
Thanks in advance
Nits

Hi

How about

=IF(C539="","",IF(ISERROR(MATCH(C539,$T$2:$T$667,0)),"record needed","record not needed"))

rylo

Thanks Rylo It works.. Wonder how it was working before..