Where to Put Captcha Code?

[eluser]Glowball[/eluser]
Hi all, I have a site with a form on every page, and that form needs a captcha. The code for the form is in a single view template used by all pages, so it is only in one place. I'd rather not put the captcha-building code in a view, but I'm not sure where else to put it.

Some of my controllers have multiple functions, so it seems like it would be best to put the code in the constructor for each controller. But then it seems that I can't return the captcha image code from the constructor to pass it to the view.

Do I need to put the code in each function? It seems so redundant. What would you do?