If you click where it says "Click here to get the plugin", you should be brought to a site providing you with information about the plugin that you need and containing a link to download that plugin. Only problem is that sometimes, it doesn't give you the correct information. For instance, one time it said I needed the "NetZip classic" plugin from real.com but turned out I just needed the Macromedia Flash plugin. Here's a link off the mozilla website with a list of common plugins and where to get them:
ok thanks. i didn't know firefox didn't have flash functionality off the bat like IE. i may be installing it for some people, but i want everything to work right off the bat for them so they dont have to click on things to make them work. so i suppose ill just add flash as part of an unattended install for it.