building a transfer button in php

in this button there are 3 databases , 2 mysql and 1 ms sql
i need a php 5.6 and a php7 version as 2 site php7 and one php5.
ill include page

i need to forms one php7 one for php5.6

1) connection script to all server i edit ip's, with include page code <?php include'connection.php'?>

all usernames are same $usernames are same on all 3 database database ,

"databasemysql1"
"username" "vault1"
"databasemysql2"
"username" "vault2"
"databasemysql3"
"username" "vault3"

check databaes for credit and enable transfair funds between databases
<?php include'transfairpagephp56.php'?>
<?php include'transfairpagephp7.php'?>

any help