PHP Forum V0.2

<?php
/*
*    +--------------------------------------------------------------+
*    | Changelog                                                    |
*    +--------------------------------------------------------------+
*    |                                                              |
*    | Version: 0.2                                                 |
*    |  0.2 > Some other minor things                               |
*    |  0.2 > Threads with new reply go to the top                  |
*    |  0.2 > No blank posts                                        |
*    |  0.1 > Simple Threads, and posts                             |
*    |                                                              |
*    +--------------------------------------------------------------+
*/

$host = 'localhost';
$username = 'forum_user';
$password = 'Awesome Password';
$database = 'forum_db';
connect($host, $username, $password, $database);

function connect($host, $username, $password, $database) {
    mysql_connect($host,$username,$password) or die("Could not connect. " . mysql_error());
    mysql_select_db($database) or die("Could not select database. " . mysql_error());

    return buildDB();
}

function buildDB() {
    $sql = <<<MySQL_QUERY
CREATE TABLE IF NOT EXISTS forum (
post_num INT NOT NULL AUTO_INCREMENT,
title VARCHAR(150),
user VARCHAR(50),
bodytext TEXT,
OP INT,
created VARCHAR(100),
last_post VARCHAR(100),
PRIMARY KEY(post_num)
);
MySQL_QUERY;

    return mysql_query($sql);
}

function post($title, $user, $body, $OP, $time) {
    $title = mysql_real_escape_string(htmlentities($title));
    $user = mysql_real_escape_string(htmlentities($user));
    $body = mysql_real_escape_string(htmlentities($body));
    $body = substr($body, 0, 2500);
    $OP ? $OP = mysql_real_escape_string(htmlentities($OP)) : $OP = 0;
    $SQL = "INSERT INTO forum VALUES (NULL, '$title', '$user', '$body', $OP,'$time', '$time');";
    mysql_query($SQL);
    $SQL = "UPDATE forum SET last_post='$time' WHERE post_num=$OP";
    mysql_query($SQL);
    $page_name = $_SERVER['REQUEST_URI'];
    header("Location: $page_name");
}

function get_thread() {
    $amount_page = 6;

    if ( !$_GET ) post_box();
    if ( $_GET ) print "<h4> <a href=\"".$_SERVER['PHP_SELF']."\">Return </a> </h4>";

    if (isset($_GET["page"])) { $page = $_GET["page"]; } else { $page = 1; };
    $start_from = ($page-1) * $amount_page;

    if ( $_GET['id'] ) {
        $OP = mysql_real_escape_string(htmlentities($_GET['id']));
        if (!is_numeric($OP) || is_float($OP) || $OP <= 0) { exit; }
        $SQL = "SELECT * FROM forum WHERE OP=$OP OR post_num=$OP ORDER BY created ASC LIMIT $start_from, $amount_page";
    } else {
        $OP = 0;
        $SQL = "SELECT * FROM forum WHERE OP=$OP ORDER BY last_post DESC LIMIT $start_from, $amount_page";
    }

    $result=mysql_query($SQL);

    //pages
    $pages = "<div id=\"pages\">";

    $pages_SQL = "SELECT COUNT($OP) from forum WHERE OP=$OP";
    $pages_result = mysql_query($pages_SQL);
    $pages_row = mysql_fetch_row($pages_result);
    $pages_total_records = $pages_row[0];
    $total_pages = ceil($pages_total_records / $amount_page);

    if (isset($_GET["page"])) { $currentpage = $_GET["page"]; } else { $currentpage = 1; };
    $currentpage = mysql_real_escape_string(htmlentities($currentpage));

    $pages .= "<span class=\"pages\">";

    if ($total_pages > 0 && $currentpage > 1) {
            $pages .= "<a href=\"?page=" . (intval($currentpage) - 1) . "\">Prev &laquo; </a>";
        }

        if ($total_pages > 1) {
            for ( $i= 1; $i <= $total_pages; $i++) {
                $pages .= "<a href=\"?page=$i\"> $i </a>  ";
                if ($i != $total_pages) {
                    $pages .=  " - ";
                }
            }
        }

        if ($total_pages > 0 && $currentpage != $total_pages && $total_pages > 1) {
            $pages .= "<a href=\"?page=" . (intval($currentpage) + 1) . "\"> &raquo; Next </a>";
        }
    $pages .= "</span>\n</div>";
    //end of pages

    print $pages;

    while ($db_field = mysql_fetch_assoc($result)) {

        $reply_am = $db_field["post_num"];

        $replyquery = "SELECT COUNT(*) FROM forum WHERE OP=$reply_am";
        $replyresult = mysql_query($replyquery) or die(mysql_error());
        while($replyrow = mysql_fetch_array($replyresult)){
            $replies = $replyrow['COUNT(*)'];
        }

        print "<div class=\"thread\">\n";
        print "<div class=\"title\">\n";
        print "<h2>" . stripslashes($db_field["title"]) . "</h2>\n";
        if ( $_GET['id'] ) {
            print "<h4>" . stripslashes($db_field["user"]) . " - " . date('H:i', $db_field["created"]) . "</h4>\n";
        } else {
            print "<h4>" . stripslashes($db_field["user"]) . " - " . date('H:i', $db_field["created"]) . " - " . $replies . " Replies" . "</h4>\n";
        }
        print "</div>\n";
        print "<div class=\"post_body\">\n";
        print "<p>" . stripslashes($db_field["bodytext"]) . "</p>\n";
        print "</div>\n";
        if ( !$_GET['id'] ) print "<h4> <a href=\"".$_SERVER['PHP_SELF']."?id=".$db_field["post_num"]."\">Read more... </a> </h4>";
        print "</div>";
    }
    if ( $_GET ) post_box();
}

function post_box() {
    print <<<POST_FORM
<a id="link1" href="javascript:display('show')"> Make Post </a>

<div id="postform" style="display:none">

<form method="post" >

    <input type="hidden" value="{$_GET["id"]}" name="OP" />

    <div class="clear"></div>
    <label for="title">Title: </label><br />
    <input name="title" id="title" type="text" maxlength="150" /><br>

    <div class="clear"></div>
    <label for="name">Name: </label><br />
    <input name="name" id="name" type="text" maxlength="150" /><br>

    <div class="clear"></div>
    <label for="message">Message: </label>Maximum of 2500 Characters
    <textarea name="bodytext" id="bodytext" maxlength=2500></textarea><br>

    <input type="submit" value="Submit" />
</form>
</div>
POST_FORM;

}

if ( $_POST && $_POST['bodytext']) {
    post($_POST['title'],$_POST['name'],$_POST['bodytext'],$_POST['OP'],time());
} else {
    get_thread();
}

?>