I'm probably overlooking something blindingly obvious, but it's nearly hometime and I'm not in the mood!

OK, I'm trying to write a storybook that has pictures attached, my users sign up and get a password, then they can upload their story and an optional picture to the storybook.

Below is the upload script - when I run it, even with no picture uploaded, I get a 500 server error. I've tried running it from the command line, but I don't get any error there. I know it probably looks hopelessly messy, but I keep changing bits to try to find out where I've gone wrong and nothing seems to help. *starts to dribble*

Help me, oh wisdomful monks, before I go insane...

#!/usr/bin/perl -w

use CGI::Carp qw(fatalsToBrowser);
#place to go when successful
$redirect = "http://www.mysite.com/soapopera/start.cgi";
#absolute location of the directory for your images
$Data = "/usr/local/www/virtual/username/soapopera/images";
#file containing usernames and passwords
$datafile = "passes.txt";
#File extensions to allow your visitors to upload.
@good_extensions = ('gif', 'jpg', 'jpeg', 'png');
#maximum file size in Kb
$max_size_main = 25;

#Gives date as "Weekday, Daynumber Month Year"
use POSIX qw(strftime);
$time= strftime("%A, %d %B %Y", localtime);

use CGI;
my $req = new CGI;
my $name = $req->param("name");
my $password = $req->param("password");
my $title = $req->param("title");
my $story = $req->param("story");
my $storyid = $req->param("storyid");
my $image = $req->param("image");
my $next1 = $req->param("next1");
my $next2 = $req->param("next2");
my $chapter = $req->param("chapter");

my $imagename = $image;
$story =~ s/\n/<br>/gi;

open(PASSFILE, $datafile) or die $!;
@data = <PASSFILE>;
close(PASSFILE);
foreach $data(@data){
@eachinfo = split(/\|/, $data);
if ($eachinfo[0] eq $name && $eachinfo[2] eq $password){
$success = 1;
}
}
if (!$success){
print "<h1>Sorry</h1>That Name/Password combination is not correct. Pr
+ess your back button and try again.";
}
if($success){

if($image) {
 $imagename =~ s/^.*(\\|\/)//;
 $imagename =~ s/ +/\_/g;

$num="";
while(-e "$Data/$num$imagename"){ $num++; }
$imagename = $num.$imagename;

my $proceed_type = 0;
foreach(@good_extensions) {
        my $ext = $_;
        $ext =~ s/\.//g;
        if($imagename =~ /\.$ext$/) {
        $proceed_type = 1;
        last;
        }
    }
unless($proceed_type) {  push(@was_not_good_type, $imagename);  }

if($proceed_type) {

if(open(OUTFILE, ">$Data/$imagename")) {
while (my $bytesread = read($image, my $buffer, 1024)) { print OUTFILE
+ $buffer; }
close (OUTFILE);
push(@file_did_save, $imagename);
} else { push(@did_not_save, $imagename);  }
}

if($max_size_main) {
    if((-s "$Data/$imagename") > ($max_size_main * 1024)) {
        push(@was_too_big, $imagename);
        unlink("$Data/$imagename");
    }
  }
 #close if file exists...

if(@file_did_save){
open (TXTFILE, ">>data/$storyid.txt") or die $!;
print TXTFILE "$chapter|$name|$title|$story|$next1|$next2|$imagename|$
+time\n";
close(TXTFILE);
print $req->redirect($redirect);
} else{
if(@was_not_good_type){ @reason = @was_not_good_type;}
if(@was_too_big){@reason = @was_too_big;}
if(@did_not_save){@reason = @did_not_save;}
print "Content-type: text/html\n\n";
print "An error occured: @reason";
exit;
}

}else{ #no pic uploaded
open (TXTFILE, ">>data/$storyid.txt") or die $!;
print TXTFILE "$chapter|$name|$title|$story|$next1|$next2||$time\n";
close(TXTFILE);
print $req->redirect($redirect);
}

}#successful password
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