Fill in the blanks in each of the following statements:

a) _____ are used to document a script and improve its readability.

b) A dialog capable of receiving input from the user is displayed with method _____ of object _____.

c) A JavaScript statement that makes a decision is the _____ statement.

d) Calculations are normally performed by _____ operators.

e) Method _____ of object _____ displays a dialog with a message to the user.