What is your question? I would think it is a pretty straight forward thing. You need HTML::Parse module. Go through lwp's documentation. It is pretty solid.

#save $var->content as html file (to match with next day's file) in th
+e normal manner (not shown here)

$var=$user_agent->get('url') ;
$parsed_html=parse_html($var->content);
$txt_on_the_page=$parsed_html->format;

#for the earlier saved html 
$old_parsed_html=parse_html($oldfile->content);
$txt_on_the_old_page=$old_parsed_html->format;


# now compare $txt_on_the_page & $txt_on_the_old_page. I have put very
+ less code with very optimistic approach. But with little effort you 
+will get what you need.
[download]