// Create a tab and add and additional tab to the main tab.
int $windowId;
int $mainTab;
 
// First create a User Window to place the control on
$windowId = `createWindow "MyWindow"`;
 
// create a main tab controller then add a second and third tab
$mainTab = `createTab $windowId "Main" "Second" "Third"`;
 
// make the third tab active
selectTabItem $mainTab 2;