33007 Mortgage Calculator

I need the following in 4 seperate files, they all kind of build up on each other. I need lots of comments so I can understand what the programmer has done and get a better understanding of how to do this myself in the future. File 1: Write a Java program using a graphical user interface that calculates and displays the mortgage payment amount from user input of the amount of the mortgage, the term of the mortgage, and the interest rate of the mortgage. Allow the user to loop back and enter new data or quit. Insert comments in the program to document the program. File 2: Modify the mortgage program to allow the user to input the amount of a mortgage and then select from a menu of mortgage loans: 7 year at 5.35%, 15 year at 5.5 %, and 30 year at 5.75%. Use an array for the different loans. Display the mortgage payment amount. Then, list the loan balance and interest paid for each payment over the term of the loan. Allow the user to loop back and enter a new amount and make a new selection, or quit. Insert comments in the program to document the program. File 3: Modify the mortgage program to allow the user to select which way they want to calculate a mortgage: by input of the amount of the mortgage, the term of the mortgage, and the interest rate of the mortgage payment (as was done in the program for File 1) or by input of the amount of a mortgage and then select from a menu of mortgage loans: 7 year at 5.35%, 15 year at 5.5 %, and 30 year at 5.75% (as was done in the program for File 2). In either case, display the mortgage payment amount. Then, list the loan balance and interest paid for each payment over the term of the loan. Allow the user to loop back and enter a new amount and make a new selection, or quit. Insert comments in the program to document the program. File 4: Modify the mortgage program for File 3 to read the interest rates to fill the array from a sequential file. Add graphics in the form of a chart. Insert comments in the program to document the program.