$connection_one = mysql_connect("server1","user","pass");
$connection_two = mysql_connect("server2","user,"pass");
mysql_select_db("db1",$connection_one);
mysql_select_db("db2",$connection_two);
mysql_query("SELECT * FROM bla1",$connection_one);
mysql_query("SELECT * FROM bla2",$connection_two);
mysql_close($connection_one);
mysql_close($connection_two);
$conn = mysql_connect("localhost", "username", "password");
mysql_select_db("database_1_name", $conn);
mysql_select_db("database_2_name", $conn);