Write a program that declares variables to represent the length and width of a room in feet, and
the price of carpentering per square yard in dollars and cents. Assign the value textbox1 to the length variable
and the value textbox2 to the width variable. Compute and display the cost of carpenting room.
There are nine square feet in one square yard. The cost is P20 per square yard.
If the cost of carpenting room is more than P500 add 10% discount.
If the cost of carpenting room is more than P1000 add 20% discount.