pass values between ssrs 2008 r2 reports

In a  ssrs 2008 R2 report, I need to pass parameters to existing subreports that are currently called.  Basically there is a main sssrs 2008 r2 report and there are 3 subreports. I would like subreports #1, subreport #2, and subreport #3 to receive the value values of customer number and customer name. I am hoping you can tell me and/or show me code that would tell me how to add parameters parameter values that are used to call these subreports.