changing class of a <span> element with JavaScript

Question

I am trying to change the class of a element with Javascript using the below code:

parent.document.getElementById('<?php echo $markid ?>').class = 'unlistened';

Not having much luck though. How do I do this properly?

Answer 1

.className rather than .class

Answer 2

Use .className instead of .class

Class is a reserved word in JS so it's changed to className. A few other HTML attributes are changed in a similar way. "for" changes to "htmlFor" for instance.