Error when calling a Sub report (Jump to report)

I have created a two reports with a parameterized query - one master and one sub report.
When I want to call the sub report from the master report I would like to be able to pass the values for the parameters in to the sub report.

And I also don′t want the passed parameters to be prompted in the sub report (so I blanked out the 'Prompt:' field).

But I got following error:
The report parameter 'parameter name' is read-only and cannot be modified.

What to do?

Running Report Server: 8.00.743.00

/Christofer

Instead of blanking the Prompt field, check the 'Hidden' checkbox.|||

Well...
Should it be in the Report Parameters dialog box where I define parameters?
If so, I can′t find this checkbox "Hidden" in my version, or where should I find it?

Regards,
Christofer