Automatically enter the server time and date in an input box on a form using JavaScript or classic ASP..?

I currently have a form written in xhtml and classic asp. The only problem I have currently the time and date have to be entered every time the user wishes to add a new record to the database. It would be much easier if they could be automatically filled in to make it more user friendly. The date needs to be in the format YYYY/MM/DD and the time HH:MM. I have looked at example scripts on the internet but have no idea were to start with this. Any help with this would be great.