Wordpress site on synology not found after changing url

[Sahara]

Hi, someone please help me....

I had no problem accessing my website from my local network at work but i got an 404 error when i tried accessing at home (it keeps directing the page to 192.168.1.100/wordpress/).

I wanted to fix this so that I am able to see the wordpress site from local and external network so I tried the link "http://codex.wordpress.org/Changing_The_Site_URL". This is what i added in the wp-config.php:

define('WP_HOME','http://arbinger.sg/wordpress');
define('WP_SITEURL','http://arbinger.sg/wordpress');

For a moment (about 5 secs) i was able to see my website from an external network but suddenly i got the 'page not found' and panicked so i followed the 'Edit functions.php'since it said that would help in case anything went wrong. I added:

update_option('siteurl','http://192.168.1.100/wordpress/');
update_option('home','http://arbinger.sg/wordpress');

in the functions.php file in my evolution theme folder but my website is still missing.

I am completely new to wordpress and php but I saw 3 different themes in my theme folder fyi (Evolution, twentyten and twentyeleven).

Please please please tell me how to fix this...