How to create detail sub report and main report in crystal?

Hello,

I want to know how to create detail sub report and main report like bellow picture in crystal from different store procedure.

In my report, the data in main report is from one store procedure and the data in detail report is from other store procedure . How can I relationship between two reports (Main report and sub report) depending Department or Month?

In the following picture, the total allowance in Department-Admin (Main report) is the total allowance of the department. The data in Detail-Allowance (Sub report) is all allowance type of the total allowance in Department (Admin) for each month.

How can I create detail sub report and main report in crystal using visual studio 2010? Please help me.