Adding a tab on the navbar using ACP

[Stefan118]

I have added some tabs to the navbar by adding a script like this in the navbar file:

PHP Code:

<vb:if condition="in_array($bbuserinfo['userid'], array(20,2000,3611,14507))">
<li> <a class='navtab' href='admincp/index.php' target='_blank'> Admin login </a>
</li> 


This worksgreat, but with every upgrade of vB i have to change the navbar script manualy becouse of this. (vB 4.1.12 -> vB 4.2.0 was a major change of this file)

In the ACP settings menu -> navigation manager you can add tabs on the navbar. (v4.2.0)
However, i can't get it to work.

Product: OK
Title: OK
Target URL: OK
Active: OK
Order: OK
Show permission name: HELP!!!!!!
Whatever i do, i get this error: Error: The specified 'show' variable is invalid.

The help says this:
Show Permission
This determines which variable(s) in the vBulletin $show array will be used to decide if the element should be displayed. For instance 'member' means it will only display if $show['member'] is true. Multiple variables can be specified by joining them with a dot. All of them must then be true for the element to display.

How do I transform the code above to a code that will be accepted?

I also don't know if and how i have to use the Tab script(s) variable.