The Ultimate Date Validation Javascript

Date1:
Date2:
This Javascript validates and converts supplied dates to dd/mm/yyyy format.
Only Valid dates will be accepted.
An alert message will appear for invalid dates and focus will be returned to the date in question.

Valid input dates =
ddmmyy, ddmmmyy, ddmmyyyy, ddmmmyyyy,
d/m/yy, dd/m/yy, d/mm/yy, dd/mm/yy, d/mmm/yy, dd/mmm/yy,
d/m/yyyy, dd/m/yyyy, d/mm/yyyy, dd/mm/yyyy, d/mmm/yyyy, dd/mmm/yyyy.

Valid date seperators =
'-' , '.' , '/' , ' ' , ':' , '_' , ','