New to PHP - Need help with Content Formatting

[xiledweb]

Ok, I would like my article submission for my audience to be as simple as possible - therefore very little knowledge of HTML would even be necessary. Everything outputs as it should right now, but the content submitted is not broken into paragraphs, i.e the text is continuous. What I want to achieve is that when the user hits 'enter', the interpretation will be that of a new paragraph (or unless there's a better way to do it).

Here is what I'm working with:
[code]// Filter out HTML code
$articletext = htmlspecialchars($articletext);

// If no page specified, default to the first page ($page = 0)
if (!isset($_GET['page'])) {
  $page = 0;
} else {
  $page = $_GET['page'];
}

// Split the text into an array of pages
$textarray = spliti('\[PAGEBREAK]', $articletext);

// Select the page we want
$articletext = $textarray[$page];

// Bold and italics
$articletext = str_replace(array('[b]', '[B]'), '<strong>', $articletext);
$articletext = str_replace(array('[eb]', '[EB]'), '</strong>', $articletext);
$articletext = str_replace(array('[i]', '[I]'), '<em>', $articletext);
$articletext = str_replace(array('[ei]', '[EI]'), '</em>', $articletext);

// Paragraphs and line breaks
function to_paragraphs($text) {
    $str = '';
    foreach (preg_split('#(\r\n|\r|\n)+\s*(\r\n|\r|\n)#', trim((string) $text)) as $p) {
        $str .= "<p>" . preg_replace('#\r\n|\r|\n#', "<br />\n", trim($p)) . "</p>\n";
    }
    return $str;
}

// Hyperlinks
$articletext = eregi_replace(
  '\\[L]([-_./a-z0-9!&%#?+,\'=:;@~]+)\\[EL]',
  '<a href="\\1">\\1</a>', $articletext);
$articletext = eregi_replace(
  '\\[L=([-_./a-z0-9!&%#?+,\'=:;@~]+)]([^\\[]+)\\[EL]',
  '<a href="\\1">\\2</a>', $articletext);

$PHP_SELF = $_SERVER['PHP_SELF'];

if ($page != 0) {
  $prevpage = $page - 1;
  echo "<p><a href=\"$PHP_SELF?id=$id&amp;page=$prevpage\">".
      'Previous Page</a></p>';
}

echo "<p>$articletext</p>";

if ($page < count($textarray) - 1) {
  $nextpage = $page + 1;
  echo "<p><a href=\"$PHP_SELF?id=$id&amp;page=$nextpage\">".
      'Next Page</a></p>';
}

?>[/code]

[fert]

nl2br()

[xiledweb]

I don't suppose you could explain a little bit more?

[alexcmm]

I'm no PHP wiz, but this is what I have that works in a contact form. This is the page that is sent to... it works for me. Don't know if this helps...

$comments=$_POST['comments'];
$comments = [b]preg_replace("/\n/","\n<BR>\n"[/b],$comments);

[fert]

[code]
$text=nl2br($text);
[/code]
this will change all the newlines to < br>s