Sessie probleem

if(isset($_POST['submit'])) {
$U = $_POST['user'];
$P = md5($_POST['pass']);

//Account check
$sql1="SELECT * FROM seven_ORA.dbo.UserInfo WHERE Account='$U' AND MD5PassWord='$P' AND [Right] > 0";
$rs1=mssql_query($sql1);
$select = mssql_fetch_row($rs1);
if (!$rs1){exit("Error in SQL");}
$count = mssql_num_rows($rs1);
$acces = $select ['[Right]'];
if($count == 1)
{

	$_SESSION['username'] = $U;
	$_SESSION['accesslevel'] = $acces;
    print("Logged in..... Click <a href=content/panel.php><strong>here</strong></a>");
	
	    }
else
{
    die('Access Denied');
}
}

if(isset($_POST['submit'])) {
$U = $_POST['user'];
$P = md5($_POST['pass']);
 
//Account check
$sql1="SELECT * FROM seven_ORA.dbo.UserInfo WHERE Account='$U' AND MD5PassWord='$P' AND [Right] > 0";
$rs1=mssql_query($sql1);
$select = mssql_fetch_row($rs1);
if (!$rs1){exit("Error in SQL");}
$count = mssql_num_rows($rs1);
$acces = $select ['[Right]'];
if($count == 1)
{
 
	$_SESSION['username'] = $U;
	$_SESSION['accesslevel'] = $acces;
    print("Logged in..... Click <a href=content/panel.php><strong>here</strong></a>");
 
	    }
else
{
    die('Access Denied');
}
}

session_start();
if (isset($_SESSION['username']))
   //If we are already logged into an active session
  $username = $_SESSION['username'];
  $accesslevel = $_SESSION['accesslevel'];
  echo"<span class='normal'>You are already logged in as $username! with $accesslevel</span>";

session_start();
if (isset($_SESSION['username']))
   //If we are already logged into an active session
  $username = $_SESSION['username'];
  $accesslevel = $_SESSION['accesslevel'];
  echo"<span class='normal'>You are already logged in as $username! with $accesslevel</span>";

echo $_SESSION['accesslevel'];

echo $_SESSION['accesslevel'];

$acces = $select ['[Right]'];
$_SESSION['accesslevel'] = $acces;

$acces = $select ['[Right]'];
$_SESSION['accesslevel'] = $acces;

var_dump($select); exit;

var_dump($select); exit;