Hi Wilco
example Web31 shows an example on the invoice tab on updatecustomer
however i do not use this technique. (passes parameters)
as alberto suggests i use a sessionvalue in my filter as well, depends on how you build the filter, I would think you need to tick the send to server checkbox on the "client-side" tab for each of your five fields, and you will need to reset the value of browsecontrol when you click your search button.
(Sometimes, i reset the browse after each field - no search button required )