Good way to compare/diff somewhat similar html pages? Especially, how to ignore the tag attributes.

Hello,I am in the process of migtrating an aspx webpage to rails.  I would
like to compare the rails page to corresponding aspx page.  Unfortunately,
 the aspx page was pre-CSS so there is a lot of formatting attributes.  Is
there an easy way to compare html elements and ignore the/specific tag
attributes?  I have been playing with hpricot and diff_lcs, but not having
much luck.

Thanks again,
Matt