//in dynam1.php
//find-
  	echo "<ul><li>You are logged in as...</li><li>" . $userdata[username] . "</li>";
	echo "<li><a href=\"{$phpbb_root_path2}profile.php?mode=editprofile\">Profile</a></li>";
	echo "<li><a href=\"{$phpbb_root_path2}login.php?logout=true&sid={$thesid}\">Logout</li>";

//replace with

  	$status = "<ul><li>You are logged in as...</li><li>" . $userdata[username] . "</li>";
	$status .= "<li><a href=\"{$phpbb_root_path2}profile.php?mode=editprofile\">Profile</a></li>";
	$status .= "<li><a href=\"{$phpbb_root_path2}login.php?logout=true&sid={$thesid}\">Logout</li>";

//then find

	echo  "<li>You are not logged in.</li>";
	echo  "<li><a href=\"{$phpbb_root_path2}login.php\">Login</a></li>";
	echo  "<li><a href=\"{$phpbb_root_path2}profile.php?mode=register\">Register</a></li>";

//replace with

	$status =  "<li>You are not logged in.</li>";
	$status .=  "<li><a href=\"{$phpbb_root_path2}login.php\">Login</a></li>";
	$status .=  "<li><a href=\"{$phpbb_root_path2}profile.php?mode=register\">Register</a></li>";

//in index.php
//at the top

<?php include("dynam1.php");?>

//in nav2.php
//find 

<?php include("dynam1.php");?>

//replace with

<?php echo $status;?>