Making the form work like this will require some custom coding on your behalf. There might be a way to do this with client side js to not have the other elements post, but I think it would be best to do this server side.
You will basically need to have an if statement check on the radio group value that was posted, then based on this use the posted values from one set of select lists or another. You will need to make use of an if statement to do this. Here is a page with more info on creating the if statements.
vbscript_conditionals.asp
The idea in pseudo code would be like this:
if request.form("Eigentekst") = 1 then
use the first set of posted values
else
use the other set of values
end if
