Write a C++ function named modify() that modifies an existing structure in a list of structures consisting of names and phone numbers. The argument passed to modify() should be the address of the structure to be modified. The modify() function should display the existing name and phone number in the selected structure, request a new name and phone number, and then display the final structure. Assume the following definition has been made: union { double rate; double taxes; int num; } flag; For this union, write cout statements to display the members of the union