d.setTime(d.getTime() + (exdays*24*60*60*1000));
number of days multiplied number of hours in a day (24), multiplied 60 minutes per hours, multiplied 60 seconds in a minute, multiplied 1000 milliseconds in a second
you get the number of milliseconds for the number of days to reach the expiration date
which is added to the current time to get the moment of expiration
u r a hero! Thank you very much!