require() results in session and header-sent errors

I'm trying to prototype the framework for some intranet applications. I begin with a login.php script. At the VERY top, of this script, I require a file as follows: require("intranet_ini.php"); This contains some constant definitions, and one function; here is the code: <? define("INTRANET_DB","intranet"); define("INTRANET_APPS_TABLE","apps"); define("INTRANET_APPS_FOLDER","apps"); define("INTRANET_FOLDER","/"); //Server Root define("INTRANET_TEST_PASSWORD","test"); function Login_Success($thisAppFolder, $thisPassword) { session_start(); global $sess_TestMode; session_register("sess_TestMode"); $sess_TestMode = ($thisPassword == INTRANET_TEST_PASSWORD); global $sess_AppDB; session_register("sess_AppDB"); $sess_AppDB = $thisAppFolder; $appBaseUrl = INTRANET_FOLDER . INTRANET_APPS_FOLDER; header("Location: $appBaseUrl/$thisAppFolder/"); } ?> The script works fine like this: it redirects the page. HOWEVER.... I've decided I want to remove the function above into it's own file, "login_funcs.php". For the time being it will be the only function in said file. I cut and pasted the function, and added: require("login_funcs.php"); directly underneath the line requiring intranet_ini.php, so in essence I am still including the very same lines of code, in the very same order. However, when the Login_Success function is called, the following errors stump me: Warning: Cannot send session cookie - headers already sent by (output started at c:\intranet\login_funcs.php:1) in c:\intranet\login_funcs.php on line 4 Warning: Cannot send session cache limiter - headers already sent (output started at c:\intranet\login_funcs.php:1) in c:\intranet\login_funcs.php on line 4 Warning: Cannot add header information - headers already sent by (output started at c:\intranet\login_funcs.php:1) in c:\intranet\login_funcs.php on line 15 PS....using include() does not solve this problem. Thanks in advance for any ideas. George M Jempty Database Administrator Regional West Medical Center Scottsbluff, Nebraska 308.630.2408