I would like to know the arguments cdt and cd that is used in the function(doc, cdt, cd) are the username and password to connect to the database? They are shortcut for what?
In other words, why we did not user db_user and db_pass?
From the other side, the cur_frm.cscript.custom_delivery_date = function(doc, cdt, cd) means to run the function once the delivery_date is entered and does not mean that it is the returned value of the the function, right?