Reportviewer Report Filter - Check Date If Null

I'm working in a c# windows application with vs2010 and a local database.In one of my forms i use a ReporViewer to display a report. I would like to be able to show results from a record in this report only if a specific field (witch is a date) is not null. I created a table and i added a filter but seems that the expression i use is wrong. I used something like this, in the Tablix Properties - Filters: expression `=IsNothing(Fields!payed.Value)` operator `=` value `=true` Any ideas?Thanks in advance! Maybe i forgot the = in the value input. It's working now!