PHP sessions unknown error

[Nighthero]

I have a website that contains a login and when the user is logged in I want it to display a message on the main page as well as carry the session on through.I am receiving the error:\[code\]Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by..\[/code\]and \[code\]Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent\[/code\]When I am not logged in it displays the error, but as soon as I log in and return to the page it disappears, but doesn't display the "You are logged in!" like it should...Here is my authentication code after it checks the database for a match:\[code\]if ($result["userName"] == $_POST[txtUsername] && $result["password"] ==$_POST[txtPassword]) { ?> <script type="text/javascript">; alert("successfully logged in, <?php echo $result['userName'];?>!"); window.location.href='http://manning3.jcu.edu.au/~jc192699/index.html'; </script> <?php session_start(); $_SESSION["access"] = 'granted'; }\[/code\]And my code in my index.php that seems to cause the error:\[code\] <?php session_start(); if ($_SESSION["access"] == 'granted'){ ?> <p>You are logged in!</p> <?php } else{ ?> <p>You are not logged in!</p> <?php } ?>\[/code\]Any help would be GREATLY appreciated. Thank you!