note 89231 added to function.substr

Just tried to Use session variable in substr function but what I find out was that, The Session variable value changes after the function. Any suggestions . echo "before - "; print_r ($_SESSION['MOBILE_CONTACT']);//gives before - 12345678 $mobile_Contact = substr ($_SESSION['MOBILE_CONTACT'], 2); echo "After - "; print_r ($_SESSION['MOBILE_CONTACT']);// After - 345678 ---- Server IP: 59.162.86.33 Probable Submitter: 121.241.113.130 ---- Manual Page -- http://www.php.net/manual/en/function.substr.php Edit -- https://master.php.net/note/edit/89231 Del: integrated -- https://master.php.net/note/delete/89231/integrated Del: useless -- https://master.php.net/note/delete/89231/useless Del: bad code -- https://master.php.net/note/delete/89231/bad+code Del: spam -- https://master.php.net/note/delete/89231/spam Del: non-english -- https://master.php.net/note/delete/89231/non-english Del: in docs -- https://master.php.net/note/delete/89231/in+docs Del: other reasons-- https://master.php.net/note/delete/89231 Reject -- https://master.php.net/note/reject/89231 Search -- https://master.php.net/manage/user-notes.php