Log-in disappears upon login?

I’m using this php web script and would like to know what happens upon log-in. I see “will auto hide when logged in”. Does this mean the log-in box disappears after log-in? Does it get replaced with something? Can you read the code below and tell me? If so, what replaces it? Thanks.

<!-- start of login box - will auto hide when logged in-->
  <div id="IndexLoginGoldBox_1">
    <!--[onload_300;block=div;when [var.show_login_box]=1;comm]-->
    <div id="IndexLoginGoldBox_2">
      <div id="IndexLoginGoldBox_content">
        <div id="RelatedVideosTitle">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="font5_14">Login and start Uploading!</span></div>
        <ul class="IndexLoginGoldBox_list">
          <form name="login" action="login.php" method="POST" class="FormIndexLogin">
              <input type="text" name="user_name_login" size="20" />
              <input type="password" name="password_login" size="20" />
              <input type="hidden" name="submitted" value="yes" />
              <input type="submit" value="Login Now" name="logi_n" />
  <!-- end of login box -->

From what I have just read in your post above and the code it seems to be the login box will auto hide after logging in, but not seeing the javascript and any other code I’m guessing.