Add the code to convert the numeric value of points earned to a letter grade. Add code to ensure that project doesn't terminate if a nonnumeric value is entered. $(90$ points$)$

Display the letter grade in the label. $(20$ points$)$

Points earned to letter grade conversion table.

$\backslash$table$[[$Points Earned,Letter Grade$],[$Less than $60,$F$],[$Less than $70,$D$],[$Less than $80,$B$],[$Less than $90,],[$Less than or equal to $100,$A$]]$

Use the values in the table above to test your work.