UML question

I have a web site that I am documenting.

It does a search process and stores the criteria choices in the session. The it goes into another page for view order details.

I displayed the activation to start of the criteria and at the end of the criteria when they come back. But, I was looking at another architects drawings for another company and he makes the activation small. And, yes since a page is delivered right after a request. I can see him make short activations.

But, since the criteria is held in session I think the activation should extend until this data is released.

Main --> || Search  --> Details 

               ||<--                <--

               ||

Which way is correct

Thanks,

Nick