What is my webpage visitors don't have flash?

I have just finished a flash web page, in the unlikely event that a visitor did not have flash installed - what would happen? What would they see and how can I insert a page that would be seen - sending them to the Macromedia site for download.

I would like to create a simple HTML page that is shown only if the visitor doesn’t have the flash plug-in, that directs them towards where to get it - how do I go about doing this?

Thanks as always

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