How to set a menu as a top or root one

Hello to all,

I am using Encore CS5.1

1)The problem.

I would like to set the first menu in the sequence as the "Root menu" (or "Top menu" depending on the remote control).

Unfortunately in the DVD I have made each time I click on the key "Top menu" the DVD comes back to a submenu.

2)The details

Let's look at the following flowchart.

I would like to transform the menu "Nicole_et_JP" (yellow circle) as the "Top menu". The problem is that when I click on the "Top menu" key on my remote control the DVD player goes to "C_etait_nous_menu" (red circle).

Maybe the numbers B2 (for the first one) and B1 (for the second one) are related to the problem.

3)The question

I have not found out the answer in the help. So could you help me to learn how to set a given menu as a root (or top) one.

Any help appreciated, thank you.

Jean-Paul