hi,
i have 2 websites with 2 diffrent DB i just want to connect (share!) the user login in the 2 websites
do i have to setup a new slave website in the master website ?
if yes then how can i share the user between the master and the slave website?

if NO and i can just connect the 2 DB how can i do that

I mean can i add a ready website as a slave one and share the users between the 2 websites?

As explained in the tutorial video 16 and several times in the forum, the sharing is a decision that is take when you create a website.
www.jms2win.com/tutorial#jms12x-16

You can not share the users between existing websites.

If you want to share the users between websites, you have to create a JMS templates in which you select the extension that you want to share in the "sharing" tabs.
You can share the user between separated DBs if your MySQL user give you the permission. The key element is to have a MySQL user that is identical between the different DB and that allow creating views. Contact your DB administrator if you don't know how to create a MySQL user identical for several DB with enough permission to create and show views.

So YES you can create a ready website that you will replicate and for which you will decide to share the users. This is what is shown in the tutorial video 16 but with the same DB. You just have to specify another DB for the second websites.

Dear sir,,,

I have installed the jms on the master website
and now I wan't to make a slave website with a new BD
based on the master BD .
thats mean that i want just to share the user in the mnaster website with the slave website
sir in the tutrial Video 16 you show us how to
share user between 2 slave website based on each other
if you can show us step by step
******how to make a slave website based on the master website
that would be help full from you***
Sir I cant get the idea from the video tutorial 16

and thank you very much for the Component
I feel that it is great but i can't do it right!
I'm very sorry for that

hope to hear from you

If you want to share the users between two separated DB, the key element is to have the MySQL User granted with the permission that allow to share the MySQL table accross DB.

This is exactly the same as you have in tutorial video 16 except that you have to define all the parameters for the new DB (host, user, password) and not only the tables prefix (when this is in the same DB).
Normally the MySQL user and password is identical between the two DB.
If you want to have different MySQL user between DB, perhaps you could you the "root" MySQL user to share the tables. See user manual and "multisites.cfg.php" configuration to provide the MySQL root login and password.

So to test, I suggest you start to create the JMS template with sharing in the same DB.
Once you are able to share the joomla user when using the same DB then you can change the DB parameters in the JMS template and re-use the rule with a different DB.
Always check the result with JMS tools or PHPMyAdmin to verify that you have correctly created the links betwwen the DBs.