can javascript from outside an update panel update a video within it?

I have a video in an iframe, and the iframe is within an updatepanel.

As far as I know, the only purpose of an update panel is to allow refresh of just part of a webpage, rather than reloading the entire page.

However, I noticed that after I put in the update panel, I had javascript that failed.  It no longer was able to make the video seek, when it was loaded.

This is 99% a bug on my part, but I just want to be sure - an update panel should not interfere with any javascript in the 'head' section from updating a video within the update panel.

Thanks