Use 0 for False, or -1 for True.
Alternatively, place a check box on a form, and refer to:
[Forms].[Form1].[Checkbox2]
or whatever instead of the [Yes or No] parameter.
It also helps JET to understand the value if you declare the parameter by
choosing Parameters on the Query menu (in query design view.)

Signature
Allen Browne - Microsoft MVP. Perth, Western Australia.
Tips for Access users - http://allenbrowne.com/tips.html
Reply to group, rather than allenbrowne at mvps dot org.
> Hello!
> This might be a silly question but;
[quoted text clipped - 10 lines]
> I would be happy for any answer!
> Best wishes from Jorgen