In this below PHP programming I came across the following error <?php $user_ip = $_SERVER('REMOTE_ADDR'); echo $user_ip; ?> it gives the error output in browser as " fatal error function name must be a string on line 2 " so after checking that code I used ('REMOTE_ADDR') instead of ['REMOTE_ADDR'] so this could be the error free coding <?php $user_ip = $_SERVER ['REMOTE_ADDR']; echo $user_ip; ?> o/p 127.0.0.1