Fluid image resizing in CSS (or JS?)

Question

I'm trying to show a fairly large image on a page on my site. I want it to be re-sized dynamically depending on the user's resolution, so that it takes up the same percentage of screen on every monitor. How would I do that?

Answer 1

Set image width to a percentage.

Answer 2

Use the percentage values rather than pixels:

<img src="path here" width="100%" />