Comparing two fields in a single table

I am creating a report on a Serenic Navigator database which has a table called "Employee Job". The concept is that there is a possibility of an employee having multiple Employee Job records. On that table are two fields: Payroll Job No. and Def. Payroll Job No. I am trying to filter the table to identify only those records where the two fields are not equal.

Here is what I have come up with so far based on my seach of the knowledge base (http://kb.jetreports.com/article/AA-00507) and the forum.

=NL("rows","Employee Job","Employee No.","Title","<>*HRWK","Payroll Job No.","=""<>""&nf(,""Def. Payroll Job No."")")

I think I'm close, but I keep getting an error that states - Invalid filter "<>".

Does anyone have any suggestions as to what I am missing here?

Many thanks,
Dave