PHP Forum V0.1

<?php

$host = 'localhost';
$username = 'username';
$password = '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),
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));
    $OP ? $OP = mysql_real_escape_string(htmlentities($OP)) : $OP = 0;
    $SQL = "INSERT INTO forum VALUES (NULL, '$title', '$user', '$body', $OP, '$time');";
    mysql_query($SQL);
    $page_name = $_SERVER['REQUEST_URI'];
    header("Location: $page_name");
}

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

    $amount_page = 10;
    if (isset($_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']));
        $SQL = "SELECT * FROM forum WHERE OP=$OP OR post_num=$OP ORDER BY created ASC LIMIT $start_from, $amount_page";
    } else {
        $OP = 0;
        $SQL = "SELECT * FROM forum WHERE OP=0 ORDER BY created DESC LIMIT $start_from, $amount_page";
    }
    $result=mysql_query($SQL);


    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 ( $_GET ) {
            print "<h4>" . stripslashes($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 ( !$_GET ) print "<h4> <a href=\"".$_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><br />
    <textarea name="bodytext" id="bodytext"></textarea><br>

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

}

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

?>