I get an exception '_formatInt not found on [object]'.
But that appears only in special cirumstances, not in normal usage: I am merging all js-files (myfaces and our own) into one single file.
If I then open a calendar popup and click i.e. the year-dropdown the exception occurs.
The '_formatInt' exists at the end of 'popcalendar.js. I found that if I move this prototype-declaration before the function declaration prior to that the exception disappears.
I don't know why...