It took me about ten seconds to permanently switch to jQuery.
Non jQuery: document.getElementById("iframe").src = url;
See what I mean?!
Here's a quote from my fav jQuery book:
Or there’s a secret that some of the biggest names on the Web—like Amazon, Google, Microsoft, Mozilla, Twitter, and WordPress—will probably be okay about us sharing with you: “Just use jQuery!” Designers and developers the world over are using the jQuery library to elegantly and rapidly implement their interaction ideas, completing the web development puzzle.