We are going to code a mortgage calculator in this application.

The first screen allows entry of the purchase price, required down payment (both must not be zero), rate type (fixed or variable, defaults to F), amortization period (defaults to 1 year), client's credit score (less than 675 is not eligible for a mortgage).

Fixed or Variable rate type must be selected. All fields must be entered. Then the second screen with overlay is displayed.

The fields used to contain the first screen values are protected from user input whenever both screens show.

Values can be entered until user presses F3 when the second screen is showing.

Find the rate based on the followingcredit score table (Prime (P) = 5.45)

Score	Fixed Rate	Variable Rate
625 <= 675	P	P - 0.1
675 <= 775	P - 0.1	P - 0.3
775 <= 870	P - 0.4	P - 0.5
> 870	P - 0.6	P - 0.8

Determining the interest paid based on the rate found using the formula:

Interest amount = mortgage amount * years * rate/100

Display fileMORTGDSP.DSPFprovided:

MORTGRPG.RPGLE: