2 Subreports in the one Report

Hi.

I have a question about how to deal with  2 Subreports in Crystal Report.

I set 2 subreports in 1 report at the details section. It was successful.

However, when the reports have 2 or more pages, one subreport rides another subreport like the figure.

I'd like the report like this image;

(Page1)              (Page2)

sub1-1                sub1-2

sub2-1                sub2-2

How can i solve this problem?