Problem with using extract function in report expression

[fml55555]

I am trying to make the headers of a list dynamic. The headers involve
Header1: Displaying the previous month and current year (Format eg: Jan YYYY)
Header2:  : Displaying the previous month and previous year  (Format eg: Jan (YYYY-1))

I am trying to use a report expression current_date and extract function to do the same, however it fails with the error RSV-VAL-0002(CRX-YXX-4010. A parsing error was found). I tried using ASofDate() but result is pretty much the same. I used the following syntax

extract(month,current_date)

[Francis aka khayman]

extract(month;current_date)