Change class name onmouseover

[kuma.lk]

I'm trying to find a way to use Javascript to find elements with a specific class, dynamically change the class onmouseover, and return the element to its original class onmouseout. Obviously there are a ton of scripts out there that have this kind of functionality, but I need something that I can put into an external javascript, without having to add anything to the markup. I've tried to hack something out, but unfortunately don't know enough about javascript to make it work.

Any ideas?

Thanks,

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