Get value from selected form_dropdown()

[eluser]danmontgomery[/eluser]
You won't be able to pass this value directly to a PHP variable on the page, because by the time the page is rendered PHP has finished processing. If you're unsure about this, I'd suggest googling the difference between server-side and client-side programming.

What you can do, however, is use javascript to interact with the page after it's loaded. You can do this by using javascript's onChange() functionality... Normally, I'd suggest using a framework like jQuery, but I'm not sure that would be helpful without first having a grasp on javascript.

I'd suggest starting here, depending on what you want to do (show/hide fields, load content, load a url, etc) this can be relatively easy or rather complicated.