Aligning button and text in navbar in twitter bootstrap

Aligning button and text in navbar in twitter bootstrap

I have written the following html with Bootstrap 2.3.2 included:
<div class="navbar navbar-fixed-top">
<div class="navbar-inner">
<div class="container">
(...)
<div class="nav-collapse collapse">
<ul class="nav">
(...)
</ul>
<form id="login-form" class="navbar-form pull-right">
<span class="navbar-text">Hello, username!</span>
<button id="logout" class="btn">Log out</button>
</form>
</div>
</div>
</div>
</div>
How can I make it so that the button aligns with the text and .navbar
correctly? Currently the button sticks to the bottom of the line, which is
the bottom of the .navbar because of the .navbar-text.