I have created a query that contains Nz functions, which acts as a search query.

I pick up the values from a form which contains textboxes and a few checkboxes.

The query works fine, but for the checkboxes I ran into difficulties using the Nz function so just set it as:

Problem is that only sets to true or false, which causes problems because say that the user isn't aware that the search requires them to click the checkbox, the correct result won't be returned.

I am aware that the checkbox has a 'triple state', is there anyway of setting this in the Nz function so that it will be true, false or could be either?