php - My Website Keeps Logging Me Out When Clicking Link To Another Page -

i having issue website sessions. built website requires user log in view webpage. works perfect under domain, when uploaded files different server temporality let client preview web page on server issue stated in title. automatically says password incorrect. can still log in fine if try navigate page within site logs out 99% of time.

i using phpsecurepages login forms @ beginning of each of web pages have

 <?php       // connect secure login       $cfgprogdir = 'phpsecurepages/';       include($cfgprogdir . "secure.php");  

this secure.php looks like

// create constant can checked inside files included. // gives indication if secure.php has been loaded correctly. define('loaded_properly', true);  // check if secure.php has been loaded correctly if (isset($_get['cfgprogdir']) || isset($_post['cfgprogdir']) || isset($_get['languagefile']) || isset($_post['languagefile'])) {         echo "parsing of phpsecurepages has been halted!";         exit();         }  // include configuration require($cfgprogdir . 'config.php');  // https support if (getenv('https') == 'on') {         $cfgurl = 'https://';         } else {         $cfgurl = 'http://';         }  // getting other variables      $phpsp_message = false;  // include functions , variables if ( !defined("functions_loaded") ) {         // check if functions loaded         include($cfgprogdir . 'objects/functions.php');         } include($cfgprogdir . 'lng/' . $languagefile);   // choose between login or logout if (isset($logout) && !(isset($_get['logout']) || isset($_post['logout']))) {         // logout         include($cfgprogdir . 'objects/logout.php');         } else {         // starting login check         if ($nodetailedmessages == true) {                 $strusernotexist = $strusernotallowed = $strpwnotfound = $strpwfalse = $strnopassword = $strnoaccess;                 }          // make post variables global         if (isset($_post['entered_login'])) $entered_login = $_post['entered_login'];         if (isset($_post['entered_password'])) $entered_password = $_post['entered_password'];          // check if login necessary         include($cfgprogdir . "objects/checklogin.php");          // check if ip allowed (if using ip-restriced access)         if ($use_ip_restricted_access==true) {                 include($cfgprogdir . "objects/checklogin_ip.php");                 }          // check login database         if ($usedatabase == true) {                 include($cfgprogdir . 'objects/checklogin_db.php');                 }          // check login data         elseif ($usedata == true) {                 include($cfgprogdir . 'objects/checklogin_data.php');                 } 

it checks php file (checklogin.php)

// check if login necessary  // check if secure.php has been loaded correctly if ( !defined("loaded_properly") || isset($_get['cfgprogdir']) || isset($_post['cfgprogdir'])) {         echo "parsing of phpsecurepages has been halted!";         exit(); }  if (!isset($entered_login) && !isset($entered_password)) {         // use data session         session_start();         // session hack make sessions on old php4 versions work         if (phpversion() > 4.0) {                 if (isset($_session['login'])) $login = $_session['login'];                 if (isset($_session['password'])) $password = $_session['password'];                 }         } else {         // use entered data         session_start();         // session hack make sessions on old php4 versions work         if (phpversion() <= 4.0) {                 session_unregister("login");                 session_unregister("password");                 }         // encrypt entered login & password         $login = $entered_login;         if ($passwordencryptedwithmd5 && function_exists(md5)) {                 $password = md5($entered_password);                 }         else {                 $password = $entered_password;                 }         // session hack make sessions on old php4 versions work         if (phpversion() > 4.0) {                 $_session['login'] = $login;                 $_session['password'] = $password;                 }         else {                 session_register("login");                 session_register("password");                 }         }  if (!isset($login)) {         // no login available         include($cfgprogdir . "interface.php");         exit;         }  if (!isset($password)) {         // no password available         $phpsp_message = $strnopassword;         include($cfgprogdir . "interface.php");         exit;         }  // login , password variables exist // continue checking them ?>