To select a field on a certain tab, you first need to show the tab.
So before you set the focus to the cc field, you need to make sure the tab is the selected tab.
To do this, you need to trigger a click on the title of the tab.
Make sure you know the ID of the link in that title and before you set the focus to the cc field, add a line similar to this one:
| document.getElementById('accrdnHyprlnk5').click(); |
In this example: accrdnHyperlnk5 is the ID of the link in the title of the 5th tab.
In this case, where you only have 2 tabs, you're id will probably be accrdnHyprlnk2, but be sure to check this.