use CGI qw(:cgi);
use strict;

my $flatfile = "somefile.txt";
my $query = CGI->new();
my $text = $query->param("text_box");

open(FLATFILE, ">>somefile.txt") or die "Open failed, $!";
print FLATFILE "$text\n\n";
close(FLATFILE);

print "Content-type: text/html\n\n";
print "Success!";