Data assist runs, but pages not working

I have been using data assist and I am having trouble getting this to work. I am getting this error when I try to view the pages produced, even the results page:

Warning: mysql_select_db() expects parameter 2 to be resource, null given in /Users/username/Sites/website/admin/images_Results.php on line 45

Warning: mysql_query() expects parameter 2 to be resource, null given in /Users/username/Sites/website/admin/images_Results.php on line 48

Basically, I have taken the back end of one site that works and put it on the back of another site and they work to a degree... some of these pages use digital file upload and that isn't working, so I thought I'd rebuild the pages I need with data assist, then reapply digital file pro, but no matter what data assist does, I just can't get the pages to work, and that's without applying the digital file pro to them! Data assist wizard runs fine, it just doesn't work once done, which is really unusual!

Any ideas?

The backend I lifted was taken from a site that was built on a Mac using the built in PHP that comes with a mac, but due to some of it's limitations, I decided to rebuild my mac and use XAMPP as my server. Now I am using XAMPP none of the file upload stuff is working.

Thanks.

Line 45:
mysql_select_db($database_localhost, $localhost);

Line 48:
$WADAimages = mysql_query($query_limit_WADAimages, $localhost) or die(mysql_error());