vaibhavmalushte (./1) :
$ Html2pdf Html2pdf = new ('P', 'A4', 'en', false, 'ISO-8859-15', 2);

what is this ? the right syntax is :
$Html2pdf = new HTML2PDF('P', 'A4', 'en', false, 'ISO-8859-15', 2);
but only for the v4.x

if you use the v3.x read the examples
and you hav not to use html, head, body tags. see the wiki about the page tag.