Passing a Form Textbox to a query parameter

[NickWren]

So I have a Textbox called SearchParameters and two more called StartDate and EndDate on a form. I got the dates to work fine, using

Between Nz([Forms]![frmSampleStatus]![StartDate],#1/1/1900#) And Nz([Forms]![frmSampleStatus]![EndDate],#1/1/2200#)

Now I want to find anything with those dates and null so in the or criteria I put Nz([Forms]![frmSampleStatus]![SearchParameters],Is Null). I even tried the SearchParameter by itself and all I get is #Name? all across the subform datasheet. Ive tried to make the textbox "Is Null", "Is Not Null", "Null", Null, and so on... I havent gotten anything to show both the dates I want and the ones that dont have dates.

[ranman256]

if you are using a form for the parameter, then it wont be null, so theres no need to put NZ in the query.
If the FORM TEXT BOX is null , set the default there.

but if you want to run with no dates, then you need 2 queries....
if IsNull(txtStartDate) then
docmd.openquery "qsQryNoDate"
else
docmd.openquery "qsQryDateRng"
endif

[NickWren]

So There is no way to show last weeks tests (uses the completion date) that were completed and the ones still in progress (aka no date for completion).
If I put Is Null in the query it will just always show those samples.