Passing a variable from a form to a query (where criteria)?

Hi,

I've only managed to find bits and parts of how to pass variables between 
forms and queries - but I really need someone to write down a simple
example 
of how to do it - and then I'll modify it from there.

WHAT I TRY TO ACHIEVE

1) In one of my queries I want to filter one of the fields with "or 
<variable1> or <variable2> or >variable3>

These 3 variables should be declared in a form (preferably with a 
radio-button, where I declare "proper" values to variable1...3 if set to
TRUE 
and a "bogus" value to varaible1...3 if set to "FALSE".

I have declared variable1 to variable 3 as variables:

Option Compare Database
Public variable1 As Byte
Public variable2 As Byte
Public variable3 As Byte
End Sub

If someone could explain:

a) How do I get radiobutton1 to write a value to variable1 and
b) how do I call variable1 in my query?

May thanks in advance!

Kindly,
Mikael
Sweden