I need to check if a cell is blank and return one letter, but if the cell is
not blank I need it to return another letter if true and a different letter
if false. I am using the following statement but I am getting a run-time
error, Application-defined or object-defined error. Would someone please let
me know what I am doing wrong?

ActiveCell.FormulaR1C1 =
"=IF(Or(ISBLANK(RC[-12])=TRUE,""f""),(RC[-12]=""CALL"",""c"",""p""))"

Thanks for any help