parameter Query (1 Viewer)

Yesterday I posted a question re. this subject in the incorrect section. Unfortunately I can't edit or delete it.

I have a parameter query which I enter parameters off a form;

1. date range
2. Events
3. Products

The date range and Events parameters work 100% but the Products parameter will only work if I have selected Date and Events as well. Note that I want a date range to always be selected so this is ok.
I want to select data based on the following;

Date + Events
Date + Events + Products
Date + Products
My problem is getting Date + Products working.

One point to note is that if Events or Products are left blank I want the report to show all data for that field(s). To achieve what I have so far I have used Or Like/Is Null when building the criteria in the Product and Event fields.

How can I get the query to return combinations of Date &/or Events & Products?

I have attached a sample database.

You can open the form, enter a date range, select an event and/or a product, and click on the command button to run the query.


If the start date text box on the form is left blank, all the dates will be returned.
.

Jon K
Thank you very much for your help. I hadn't thought of approaching my problem from your angle. It works very well.