Error Login design.inc.php

I have a serious error that occurs when a user tries to access your account in the popup. I get the error. Could you help please? I have version 7.0.9

Warning: Cannot modify header information - headers already sent by (output started at /home/plazavip/public_html/acostadas.com/member.php:2) in/home/plazavip/public_html/acostadas.com/inc/design.inc.php on line 147

Warning: Cannot modify header information - headers already sent by (output started at /home/plazavip/public_html/acostadas.com/member.php:2) in/home/plazavip/public_html/acostadas.com/inc/design.inc.php on line 148

Warning: Cannot modify header information - headers already sent by (output started at /home/plazavip/public_html/acostadas.com/member.php:2) in/home/plazavip/public_html/acostadas.com/inc/design.inc.php on line 149

Warning: Cannot modify header information - headers already sent by (output started at /home/plazavip/public_html/acostadas.com/member.php:2) in/home/plazavip/public_html/acostadas.com/inc/design.inc.php on line 150

Someone can tell me how to fix it please?

If you have recently tried to modify either member.php or inc/design.inc.php then restore it from the origional dolphin zip for for 7.0.9

The error headers already sent is usally the result of white space existing at the end of the file just after the closing ?> php tag.

Deano92964 thank you very much for your help, and although not really noticeable, but if there was a blank space in file member.php at the end.

The error occurred when trying to make the user to enter the program redirects to index.php but I worked and leave everything as it was quice original realize leaving the space blank. Thanks again for your help.