note 108668 added to function.mcrypt-encrypt

below is my encryption function, it is working well with php5.3 but when i try to use the same in php5.1, it doesnt work the program terminates before encrypting...Its neither giving a syntax error while compiling...please suggest where i am going wrong..... function encrypt($string) { //Key $key = "xxxxxxxx"; //Encryption $cipher_alg = MCRYPT_DES; //MCRYPT_TRIPLEDES; $iv = mcrypt_create_iv(mcrypt_get_iv_size($cipher_alg,MCRYPT_MODE_ECB), MCRYPT_RAND); $encrypted_string = mcrypt_encrypt($cipher_alg, $key, $string, MCRYPT_MODE_ECB, $iv); return base64_encode($encrypted_string); return $encrypted_string; } ---- Server IP: 69.147.83.197 Probable Submitter: 202.54.181.143 ---- Manual Page -- http://www.php.net/manual/en/function.mcrypt-encrypt.php Edit -- https://master.php.net/note/edit/108668 Del: integrated -- https://master.php.net/note/delete/108668/integrated Del: useless -- https://master.php.net/note/delete/108668/useless Del: bad code -- https://master.php.net/note/delete/108668/bad+code Del: spam -- https://master.php.net/note/delete/108668/spam Del: non-english -- https://master.php.net/note/delete/108668/non-english Del: in docs -- https://master.php.net/note/delete/108668/in+docs Del: other reasons-- https://master.php.net/note/delete/108668 Reject -- https://master.php.net/note/reject/108668 Search -- https://master.php.net/manage/user-notes.php