Error 500 - Internal Server Error, What's not right?

[VATA1]

So, I have had someone working on my site on another host, converting it form HTML to PHP. I am now moving the site over to Zymic. I have created the databases in MySQL, and I have tried EVERYTHING to try and make my website, http://vata.vndv.com/ work. I know basically nothing about how PHP works. So, here is what my .htaccess file has, where I believe the problem lies.

RewriteEngine on
RewriteBase /www/vndv.com/v/a/t/vata/htdocs/
RewriteRule ^main.php$ main.php [QSA,L]
RewriteRule ^([a-zA-Z0-9]+)\.php$ main.php?page=$1.php [QSA,L]Options All Indexes


Basically, whenever my site loads, it uses main.php as the template for all the other pages, and the other pages just fill in the one area that changes on every page. I have a dbclass.php file on my server that is used to connect to the MySQL database. Here is what that file says.

<?php
if(!defined('INDEX')) die();
class db {

protected $con;
public $result;

function __construct($host='localhost', $user='vata_(my username)', $pass='(my usernames pass)', $base='vata_(my DB)') {
$this->con = mysql_connect($host, $user, $pass);
mysql_select_db($base, $this->con);
}

function __destruct() {
mysql_close($this->con);
}

function fetch_array($sqlquery) {
$this->result = array();
$this->q = mysql_query($sqlquery, $this->con);
while($this->tempresult = mysql_fetch_assoc($this->q)) $this->result[] = $this->tempresult;
}

function fetch_result($sqlquery) {
$this->result = array();
$this->q = mysql_query($sqlquery, $this->con);
if($this->q) $this->result = mysql_fetch_assoc($this->q);
}

function query($sqlquery) {
$this->result = mysql_query($sqlquery, $this->con);
}
}
?>

I have absolutely no clue why it just wont connect. Yes, my username is less than 16 characters. Any input is much appreciated!


***Problem has been fixed***