Why is this php script making my form dissapear?

[kryptobs2000]

If I comment out the if else branch the form displays fine, if I leave it the page is totally blank. This is how pretty much every tutorial I've read seems to handle forms, what's the problem?

    <?php
    // Check for authentication
    include('includes/variables.php');
     
    include('includes/header.php');
     
    if ($_POST("postSubmit") == 'Submit')
    {
      ;
    }
    else
    {
      ;
    }
     
    ?>
     
    <!-- This form may need work -->
    <form action="newpost.php" method="post">
    <h5>Title:</h5> <input type="text" name="title" /><br />
    <h5>Post:</h5>  <textarea name="body"></textarea>
    <input type="submit" name="postSubmit" value="Submit" />
    </form>
     
    <?php
    include('includes/footer.php');
    ?>

edit: nevermind, newb mistake. Indexing the $_POST array with () instead of [].