php和oracle的页面登录问题

Conn.php页面：
[code=php]
<?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());
}
//echo "This is a test!";
?>
[/code]
经测试，此页面没有问题。


登录页面问题部分：
[code=php]
include('conn.php');

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