meta tags for facebook share

Hi....I have managed to set up facebook share with community polls, but can't find a way of changing the text to display each poll title.

I have set meta properties in the html section of index.php for my template which facebook reads correctly. For non-joomla sites it is easy to edit the meta properties into each html page, but joomla doesn't have any!

How can I set meta properties for each poll page? I have tried adding an html section into viewpoll.php but couldn't get them to be picked up by facebook.

Any help gratefully received!?

Thanks,

Chris.