# The next page of the story exists (and hasn't snuck in
   # while we were writing a different new page).
   # Read it in and display it.

   if (!(open(STORY, "<$nextfile"))) {
      print "Could not open file $nextfile to read it!<br>\n";
   } else {
      # Read data from story file:
      $author_name = <STORY>;
      $author_email = <STORY>;
      $chapter_title = <STORY>;
      $next_text_1 = <STORY>;
      $next_text_2 = <STORY>;

      chomp($author_name);
      chomp($author_email);
      chomp($chapter_title);
      chomp($next_text_1);
      chomp($next_text_2);

      $chapter = 1 + $in{'chapter'};

      print "<b><font size=+2>Chapter $chapter: $chapter_title</font></b><p>\n";

      if (($author_name ne "") || ($author_email ne "")) {
         $author = "$author_name 
                    <a href=\"mailto:$author_email\">$author_email</a>";
      } else {
         $author= "an anonymous author";
      }
      print "<center><i>this page added by $author</i></center><p>\n";

      while (<STORY>) {
         print $_;
      }

      $next_num_1 = 2 * $in{'next'};
      $next_num_2 = $next_num_1 + 1;

      # Do some fancy formatting on the chapter numbers, so that they
      # don't print out in scientific notation.  This only becomes 
      # important when users enter chapters more than 50 levels deep. !!!
      $next_num_1 = format_chapter_number($next_num_1);
      $next_num_2 = format_chapter_number($next_num_2);

      print <<EOF;
<p>
<hr>
<p>
What do you do now?

<p>
<table>
<tr>
<td valign=bottom>
<a href="story.pl?next=$next_num_1&chapter=$chapter"><img 
src="$image_url/pink_story_arrow.gif" width="15" height="16" alt=""
border=0></a>
</td>
<td valign=top>
<a href="story.pl?next=$next_num_1&chapter=$chapter">$next_text_1</a>
</td>
</tr>

<tr>
<td valign=bottom>
<a href="story.pl?next=$next_num_2&chapter=$chapter"><img 
src="$image_url/green_story_arrow.gif" width="15" height="16" alt=""
border=0></a>
</td>
<td valign=top>
<a href="story.pl?next=$next_num_2&chapter=$chapter">$next_text_2</a>
</td>
</tr>
</table>


<p>

EOF
   }


} elsif ($in{'submit'} eq "") {
   # The next page of the story doesn't exist.
   # Ask the user to enter it.

print <<EOF;
<h1>Your Turn</h1>

You have reached the end of the story action.

<p>Now it's your turn to enter what happens next in the story.

<blockquote>

<form action="story.pl" method="post">
<b>Your name: </b> (optional) <br>
<input type="text" name="author_name" size=50 maxlength=50> <br>

<b>Your email address: </b> (optional) <br>
<input type="text" name="author_email" size=50 maxlength=50> <br>

<br><b>The next part of the story:</b> <br>
<textarea rows=10 cols=60 name="story_text" wrap="physical"></textarea> <br>

<br>
<b>The two things the reader can do next: </b><br>
Option One: <input type="text" name="next_text_1" size=60 maxlength=100> <br>
Option Two: <input type="text" name="next_text_2" size=60 maxlength=100> <br>

<br>
<b>A title for your chapter:</b> <br>
<input type="text" name="chapter_title" size=60 maxlength=80> <br>

<input type="hidden" name="next" value="$in{'next'}">
<input type="hidden" name="chapter" value="$in{'chapter'}">

<br>
<input type="submit" name="submit" value="Enter it!">
</input>

</form>

</blockquote>

EOF

} else {
   # The user has entered a next page.
   # See if it's okay.  If it is, save it.

   # Convert newlines to <br> html in the story:
   $in{story_text} =~ s/\n/<br>\n/gio;

   # Don't let people create any old file:
   $prev_page_num = format_chapter_number(int($in{'next'} / 2));
   if (($in{'next'} ne "1") && (! -e "$story_dir/$prev_page_num.txt")) {
      print "<b>Invalid chapter name!</b><br>";

   # Check for any missing text:
   } elsif ($in{story_text} eq "") {
      print "<b>Please write the description of what happens now.</b><br>";
      print "Press your browser's 'Back' button to add it.";
   } elsif (($in{next_text_1} eq "") || ($in{next_text_2} eq "")) {
      print "<b>Please enter two options for what the user can do next.</b><br>";
      print "Press your browser's 'Back' button to add this.";
   } elsif ($in{chapter_title} eq "") {
      print "<b>Please enter a title for your chapter.</b><br>";
      print "Press your browser's 'Back' button to add it.";
   } else {

      # Make sure file is still available.
      if (-e $nextfile) {
         print <<EOF;
<p><b>Ooops!  Someone else entered this section of the story 
while you were typing.  I can't enter your section</b>.

<p><center>
<a href="story.pl?next=$in{'next'}&chapter=$in{'chapter'}&reload=$bignum">See it</a>
</center>

<p><b><blockquote><blockquote><blockquote><blockquote>After you select the
"See it" link, you may need to press the 'Reload' button on your browser 
to see what the other person 
entered.</blockquote></blockquote></blockquote></blockquote></b><br>
EOF
      } else {

         # Save it!
         if (!open(STORY, ">$nextfile")) {
            print "Oh oh.  I couldn't open the file '$nextfile' to save your
                   section.  (Error: $!)  So I didn't save it.\n";
         } else {
            print STORY "$in{author_name}\n";
            print STORY "$in{author_email}\n";
            print STORY "$in{chapter_title}\n";
            print STORY "$in{next_text_1}\n";
            print STORY "$in{next_text_2}\n";
            print STORY "$in{story_text}\n";
            close(STORY);

            print <<EOF;
Your addition to the story has been saved.