Multiple TinyMCE can cause the browser focus error

Description

Steps to reproduce
1. From the Alloy sample site, create a pagetype with two TinyMCE fields.
2. Enter something in the first field.
3. Switch to another window or program.
4. Switch back but set focus to the second TinyMCE field.
5. There is a problem with the javascript function that tries to set the focus back to the first TinyMCE field.