Questions Help using parameters

Good afternoon,

I am pretty new to the Report Designer and writing my first report from scratch to list Subcontracts and their financial statuses. Got the data I want to display but am now stuck (all afternoon) trying to get a parameters to work. The field I have on my report and which gives me the data I want is POOrder.OrderNbr, subcontracts are orders of ordertype RS...I'm golden.

You learned folks on this forum have led me to think that a parameter should be added via the Schema Builder on the parameters tab. I have added a parameter named OrderNbr, datatype = String and ViewName set to =Report.GetFieldSchema('POOrder.OrderNbr') 

Prompt is OrderNbr

When I run the report I get the parameter screen pop up but there is never anything there for me to select...obviously I am missing something with my syntax or another step. I get exactly the same problem when I try this with Generic Inquiries as well and therefore am led to conclude it's a common problem with the nut that keeps the seat and keyboard together 🙁

Thank you in advance.

Ian