Php database connection using mysql

<?php
// localhost connection
        $connection=mysql_connect("localhost","root","") or die("server not found");
        $connect=mysql_select_db("databasename",$connection) or die("db not found");

// server connection
        $connection=mysql_connect("serverhost(e.g 123.12.12.12)","username","password") or die("server not found");
        $connect=mysql_select_db("databasename",$connection) or die("db not found");

?>