Setting parameter in a subform

[acotgreave]

Hi,
This is my first post...

Anyway, I have a form, frmTest, with a subform, frmTestResults.

The subform displays the results of a query which has a single parameter, "TestID".

Using VBA, I want to open frmTest in response to a button press on another form, using DoCmd.OpenForm, and setting the OpenArgs property to the TestID I want to display.

In the VBA, how do I set the parameter value of the subform so that it automatically runs the query and displays the correct results?

Thanks,
Andy