// in login.php
Session_Start();
If (IsSet($_SESSION['userid']) && $_SERVER['REMOTE_ADDR'] == $_SESSION['ip']) {
	Header('Location: draatcp.php');
	Exit();
}

// in secure page
Session_Start();

If (!IsSet($_SESSION['userid']) && $_SERVER['REMOTE_ADDR'] != $_SESSION['ip']) {
	Header('Location: login.php');
	Exit();
}

// in all pages to read username for in welcome message

Session_Start();

If (IsSet($_SESSION['userid']) && $_SERVER['REMOTE_ADDR'] == $_SESSION['ip']) {
	$navigation .= "<tr class='time_top'><td align='left' colspan='4'>Welcome <b>".$_SESSION['username']."</b>, <a href='/logout.php'>logout</a> </td><td colspan='4' align='right'> ".date('F d,  H:i')." GMT-5</td></tr>";
}