You will also need to add width tags climbing up the tree to make overflow work. Width: 100% on the tables, tr, and td's (possibly not all of them, I didn't test it fully.)

(And you can't put pre in a span, so change the span to a div like drawkbox said.)

But use overflow: auto not overflow: scroll.

And if you are worried about vertical scroll use x-overflow: auto (doesn't work in opera though).