Change date format & Fill automatically portal user ID ?

Hello,

I have imported a Module to Visual Composer from a backend system. I have 4 input parameter's. Two of them are of type date.

1] When ever I am entering a date in mm/dd/yyyy format, it is automatically getting converted into mm.dd.yyyy while executing & My backend function module is not responding to this date format & is not able to fetch data. I would like to change the date format to mm/dd/yyyy while supplying as a input to backend Function Module,irrespective of user input.

2]I have a input field as userID,my requirement is to fill it automatically with the portal UserID,through which user has logged in.

Does any one have idea about it?

Regards,

Sunil Kulkarni