PollDaddy plugin - embedded pop-up survey, but page menu bar lays on top

Hi everyone, my site is http://supermarketsafety.net/survey. My question is the about "Poll Daddy".com plugin. I've installed the plugin, registered with the site and created a survey, and followed their instructions to embed the javascript HTML code into the page where I wanted the survey window to "pop up" on top of the page contents.

The problem is that now, the page menu bar continues to show up on top of the survey pop-up window - which is distracting and weird-looking for those trying to take the survey. Has anyone encountered a similar problem, or have ideas on how to fix this thru Poll Day or Word Press?

Thanks very much.