<?php
$dbvars = array('localhost', 'rightnow_chat', 'rightnow_rnhchat', 'tyler121514');
list($dbh, $dbn, $dbu, $dbp)=$dbvars;
$dbc = new mysqli($dbh, $dbu, $dbp, $dbn);
$user = $_POST['reg_user'];
$sql = "SELECT * FROM users WHERE user = '$user'";
$dbc->query($sql);
$dbc->close();
?>