[Dave]

sessionurl contain "s=sessionhash&"
sessionurl_q contains "?s=sessionhash"
sessionurl_js contains "s=sessionhash&"

In case you weren't using any other parameters, sessionurl_q would of been fine to use but since you want to add another parameter to the URL and you don't know whether the sessionurl is set or not, you have to make use of sessionurl so you're sure the URL will come out the right way.

The search.php URL should work like this:
search.php?{session.sessionurl}do=getdaily&con tenttype=vBForum_Post&tabi d=49