Filter datawindow question

I am trying to setup a filter on my datawindow on a couple of datetime columns.  I'm sure its something simple but I have not been able to figure it out.

My filter is:

if(daysafter(dateacquired,datesold) > 0, datesold > datetime('01-01-2013') and datesold < datetime('12-31-2013'), dateacquired > datetime('01-01-2013') and dateacquired < datetime('12-31-2013'))

I can do either of the if conditions no problem.  The problem seems to be with my if.  I tried if(datesold > dateacquired, ...

The error I get it "expecting NUMBER expression"

Using PB 10.2.1 and also tried on PB 10.5