if ($_SERVER["REMOTE_ADDR"] == "127.0.0.1") {
 
    $l = mysql_connect ("localhost","root","") or die("Error connecting: <br /><br />".mysql_error());
    mysql_select_db("local_db") or die("Error getting db: <br /><br />".mysql_error());
   
    $siteurl = "http://website.dev/"; // WITH TRAILING SLASH!

 
} else {
 
    $l = mysql_connect ("localhost","live_database_user","live_password") or die("Error connecting: <br /><br />".mysql_error());
    mysql_select_db("live_db") or die("Error getting db: <br /><br />".mysql_error());
 
    $siteurl = "http://website.com/"; // WITH TRAILING SLASH!
}

http://www.mediaextra.net/2010/workflow/tips-on-local-development/

Here's a little trick I started using when working with XAMPP for localhost and keeping things in tune with the live configuration variables such as username and passwords to mysql (or whatever you're writing for).

The example below figures your working on http://website.com and that your local development server uses no password for the database.

PHP Smart Config File

mysql, php

PHP