alhitary on "add code in gallery which refer to my domain"

Dears,

I'm doing my website in my local host and make pages with galleries like bellow code :-

<dt>
<a href='http://localhost/ar/wp-content/uploads/2013/02/1.jpg' title='1'>
<img width="150" height="150" src="http://localhost/ar/wp-content/uploads/2013/02/1-150x150.jpg" class="attachment-thumbnail" alt="1" /></a>
</dt>

After i finish all pages and make backup and import the backup to my online domain, the images not shown and when i check i found them in links which refer to "http://localhost/ar/..."

what is the code i can add which will work in local host and my online domain ?

Like : src="<?php header_image(); ?>" which refer to header image without add the domain link.

Wish someone help