How can I check if a site has a virus on it or not?
 

Thanks for your answers.

view source and search for bogus javascripts or iframes

<script>....</script>
<iframe>...</iframe>

Thank you.

And how would a bogus javascript or iframe look like?

Doesn't McAfee SiteAdvisor do that?

Install a virusprogram and click the link...

So if I have, let's say AVG installed, and I click on a site with viruses, will AVG warn me?

its like firefox with norton antivirus says "WARNING! ATTACK SITE!" the you can click ignore or continue. That is your norton picking up harmful shit that is embedded.