plz tell me how one can differentiate query from organic and ppc campaign?

plz tell me how can i differentiate ppc query from organic query when the landing page is same. i have put conversion code on thanks pages. how can it differentiate query filled by ppc visitor and organic visitor.
secondly if ppc visitor fill up the query on different page which is different from landing page is it possible to distinct the query fillled by ppc visitor and organic visitor

See original post by gajendra.gets