How to delete a page if sub report is blank?

Hello,

I have an ASP.NET application written in C# with the Crystal report. Each page of this report has a header, which always has data, and also a sub report Notes that can be blank. I don't want to show pages that have blank sub report, I need to remove them completely. Without a header this would be pretty simple, but I cannot figure out how to do this in my case.

I'd appreciate your help. Thank you.