Query criteria expression builder for criteria from a form

[TechRW]

I have the following progression from form to report.

1) Open form which contains Field 1 - Name of product, Field 2 - Start date, Field 3 - End date, Button - Start Macro

2)Button activates Macro which calls for query, saves query, opens report for printing, and closes query
Note: query date criteria expression = Between Forms![Field 2] And Forms![Field 3] (this is rough only, don't have problem with this bit)
Criteria for Name of product is currently Forms![Field 1] (basic type expression) which works also.



What I would like to happen.
That if the product text box on the form is left blank that the query returns all products between the two dates.

Problem Here
What I have tried - IIf(Forms![Field 1]<>"",Forms![Field 1],Is Not Null) (also Is[Not]Null)
IIf(Forms![Field 1]="","",Forms![Field 1])

Endless frustration here.
Please help.
What am I doing wrong?
What is the correct criteria expression for what I would like to happen?

Regards
TechRW

[June7]

There is no need to 'call' a SELECT query, just open the report that uses the query as RecordSource.

If you are using controls on a form to input filter criteria, those controls must be UNBOUND, otherwise will change data in record.

WHERE datefield BETWEEN Nz(Forms!formname![Field 2], #1/1/1900#) AND Nz(Forms!formname![Field 3], #12/31/2900#) AND [Name of Product] LIKE "*" & Forms!formname![Field 1] & "*"