How to pass data from sub report to main report

I am writing a report in Crystal Reports 2008.
I have two different servers with identical SQL databases, however diferrent companies. I need to list the ticket data from both into one report and group them by the same basic criteria but one carrier ID that is in both systems. I have tried using the Shared Variable, but when I do this it brings only the ticket data from the sub report to the main report not showing any ticket data of the Main report. I am definitly missing something but I dont know what. All the tables are literally identical as it's the same software same vendor.
Example: Sub Report
WhilePrintingRecords;
Shared StringVar MDeliveryAddress:={Tkhist1.DeliveryAddress1}
Main Report
WhilePrintingRecords;
Shared StringVar MDeliveryAddress

Returns only ticket data of the sub.

Any help would be greatly appreciated

Thanks!