BV Grading scales

Create a new solution to determine the following:

When the form loads, ask the user which grading scale they want to use (AP/Honors or Regular BVHS)?

Based on their response, your code will use the appropriate scale to determine their letter grade based on the percentage entered into the text box.

Visit page 17
https://brandonvalley.k12.sd.us/district/Central_Admin/Student_Handbook/2015-2016%20Student%20Handbook-FINAL.pdf

Your form will consist of:
    a textbox for the grade percentage to be typed in
    a label to display the letter grade
    a button to calculate the letter grade
    a button to change the grading scale (you may be able to use the same message box from the start)
    a Clear button (set focus on textbox)
    an Exit button

Only allow for numbers to be typed into the textbox.

When the text is changed, the letter grade should clear.

Name the controls used in the code with the appropriate 3 letter abbreviation.

The grading scale being used should show up in the title of the form.