Wierd cookie behaviour

Hi All, I'm scratching my head a bit here. I have a form handling script that branches dependent on whether a user has admin privileges over the application. Here's the function that tests this: function isAdmin($user){ global $chan; $query = "SELECT isadmin FROM csw_user WHERE username = '" . mysql_real_escape_string($user) . "'"; // echo "<p>$query</p>\n"; $result_table = mysql_query ($query, $chan) or die ("Error: Can't retrieve the data"); if ($result_row = mysql_fetch_array ($result_table)){ $canAdminister = $result_row['isadmin'] > 0; } else { $canAdminister = FALSE; } return ($canAdminister); } Note the commented echoing of the query, which I uncommented during debugging. This function was failing with the message from die() "Error: Can't retrieve the data". On uncommenting the echo statement, I got: SELECT isadmin FROM csw_user WHERE username = '' IOW, there was a blank string passed to the isAdmin function. So I checked at a higher level and temporarily modified the code to read: echo "<pre>"; print_r ($_COOKIE); echo "</pre>\n"; $canAdministrate = isAdmin($_COOKIE['username']); This showed that $_COOKIE['username'] contained the username of the logged-on user as I expected, yet that username was not passed to the isAdmin function 8-/ FWIW, I've resolved the issue in that it no longer happens. I'd forgotten to put the opening and closing html, head, and body tags and the issue went away as soon as I did that. However, I'd appreciate info on why as I need to run some scripts within a validated user session where those scripts do their processing and then use the header function to redirect the browser to an appropriate page. TIA, -- Geoff