php和oracle的一些连接问题

2个页面：
conn.php
PHP code:

<?php
$con = oci_connect("finaltest","finaltestpw","(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 172.19.101.72)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = ENGDB01)
))
");
if (!$con)
{
die('Could not connect: ' . oci_error());
}
?>



login.php
PHP code:

<?php
session_start();
//session_unregister('bs_Account');
//session_unregister('bs_Role');

echo 'Login...';

if ($_POST['username'] == "")
{
echo "<Script language='JavaScript'> alert('Please enter username');</Script>";
echo "<script>location.href='index.php'</script>";
exit;
}

include('conn.php');


$sql = "SELECT * from `user` WHERE `Account`='".strtolower($_POST['username'])."' LIMIT 1";
$result = oci_parse($con,$sql);
oci_execute($result);
if (oci_num_rows($result) == 0)
{
echo "<Script language='JavaScript'> alert('Username error!');</Script>";
echo "<script>location.href