Salutes from Italy.

I have a problem.

 I have realized a Mask that, inserted the Date of Beginning and End,
visualizes the Data in a Report.
I have the following Situation pressing the Push-button Starts:

http://docs.google.com/Doc?id=ddbn76h4_652z8nw48cz

How I make To verify when the Report is Empty,
and to avoid that shielding appears empty?

Exists some property that verifies the Report Has not given?

Thanks to All, Hello