Write a program to calculate and display the total cost of a customer's purchases at a convenience store. Use text boxes to obtain the user's inputs for gallons of gas, apples, and donuts. Gas costs $3.359 per gallon. Apples are 65 cents each and donuts cost 75 cents each. You must apply sales tax to the purchase of the donuts. The apples and gasoline should not be taxed.

When the user clicks a button, the program must display the total cost of purchasing the desired amounts of gas, apples, and donuts in a label. Be sure to concatenate a dollar sign ( $ ) to the total cost of the customer's purchases.

Your program must use variables and constants where appropriate, even though this program could be written without using variables. Remember that is very important for your code to be easy-to-understand and easy to upgrade. Provide Clear and Exit buttons and make sure that the focus moves correctly. Name the project Convenience Store. Your program must follow the Coding Standards. You could lose many points for violating the Coding Standards (e.g. poor spacing, incorrect indentation, incorrect prefixes, etc.)

Preconditions:

• The user will only enter numerical values and will not enter letters or symbols.
• The user will enter whole numbers between or including 0 and 100.

Staple your printouts in the following order:

1. VB code
2. Interface Sketch
3. The screen capture of your actual form window at runtime after a successful test case in which 2 gallons of gas, 2 apples, & 2 donuts are purchased. Be sure to press the Alt key if necessary so your underlined accesss keys are displayed before you do the screen capture (Alt F14).
4. Microsoft Excel Test Plan
5. Programming Assignment Check-Off Sheet