$key = '6yOFZuQis%7$oF_[M89=EV!a}\mzb7=B';
$iv = 'Fa)=zx"h^O8t.-s4nO-q#vTp,,ft;fCj';
$data = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, serialize($data), MCRYPT_MODE_CBC, $iv);
$data=base64_encode($data);
above code works in localhost without any errors with encrypted value.but while uploading line number 3 ($data=mcrypt) shows error as
Fatal error: Call to undefined function mcrypt_encrypt() in demo.php on line 3..... i cant understand what is the error.I googled about it but i didnt get answer.