#!/usr/bin/perl -w
use strict;
use HTML::Parser;

my $p = HTML::Parser->new(	
		start_h => [\&Start, 'tagname, attr, text '],
		end_h => [sub { print  shift;  }, 'text'],
		comment_h => [sub { print  shift;  }, 'text'],
		default_h => [sub { print  shift;  }, 'text'],
	);
	
	open (IN, "<form.template") or die "Couldn't open!:$!";	# Your html
	my $content = '';
	{
	local $/=undef;
	$content = <IN>;

	}

	$p->parse($content);

	close(IN) or die "Couldn't close:$!";

################################################
sub Start{ 
	my ($tag, $attr,$text) = @_; 
	

	if ($tag eq 'mytag'){
		$text = "WHATEVER YOU WANT TO REPLACE HERE.
	}

	print $text;


}