calculation depreciation costs

enter a cost (dollars) for an asset along with its expected life (years)

then the resulting depreciation amount and book value (remaining value after depreciation) should be calculated and displayed for each year of the assest's lifetime - using both methods

methods:

straight-line method: calculates depreciation amount (cost / expected_life) that is equal amounts spread out over the lifetime of the item. each year the book value is subtracted by the depreciation amount

sum-of-digits: uses the sum of the years' digits and varying proportions to determine each year's depreciation amount.

would like to be able to enter varying cost and expected life pairs before deciding to end the program

must use sentinel control repeition when entering values for the cost of the assest and its expected life until the user wishes to end the program

nested repetition must be used for the counter-controlled loop dependent on the expected life

PLEASE PLEASE HELP!!!!