get/set ReportViewer 2010 paramaters via javascript

[mbowles]

I have the ReportViewer running in a portal product. The page has numerous portlets. In the portlet housing the RV, I pickup a session value to set as one of the parameters. All is well. But... I need that parameter to be picked up when the View Report button is clicked as well. Thus if a user changes the paramater via a different portlet, the page load event of the RV should get that new value from session. This works for first load, but the View Report button fires a submit that apparently ignores the hosting pageload. Is 2010 still using an IFrame to render the entire RV component? Can I set these via javascript or override the ViewReport postbackevent?