Passing multiple variables to a query

Greetings.

I have a problem that I have too little experience to solve, so I hope you guys can point me in the right direction:

I have 5 comboboxes with Name, Activity, Product, Project and Customer.
I want to create a report based on a query in which I freely can use 1 or more of the above criterias, i.e:
Just Name, or Name AND Project, or Project AND Product AND Name, or Customer AND Name, or just Customer, or.... well I think you get the scenario.
IS THIS AT ALL POSSIBLE IN JUST ONE QUERY?
or how will I go about to get this report to become real?

Hope you can help me...

Each of the combo boxes could have a default '<All>' value which means if you don't select a value it will return all values.

The way to get <All> is something like the following using Customers Table as an example.

Set the combo box row source to ....

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1. SELECT '*' AS CustID, '<All>' AS CustName
2. UNION
3. SELECT CustID, CustName
4. FROM Customers;

Mary

I've got to be stupid, but I dont understand at all...

I thought that the query should be the issue..
Something like

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1. SELECT * FROM Projectdata WHERE Projectdata.Name  = cboName.Value AND Projectdata.Activity = cboActivity.Value AND Projectdata.Customer = cboCustomer.Value 

and so on...
But that SQL-code assumes that every cbo-box.Value really has a value in it.
If I try this and only choose values from one or more, but not all cbo-boxes then the query results in nothing.

Or am I totally lost? :-/