Problems - Correcting Logic and Code Errors

Problems - Correcting Logic and Code Errors
The following sample of code contains errors. Rewrite the incorrect statements to correct all errors.
Structure ExamGrades
Public decExam1 As Decimal
Public decExam2 As Decimal
Public decExam3 As Decimal
End Structure
--------------------------- Private Function CalcAverage(ByVal grades As Decimal) As Decimal
' calculates and returns the average grade
Dim decSum As Decimal
decSum = grades.Exam1 + grades.Exam2 +
grades.Exam3
Return decSum * 3
End Function ---------------------------
Private Sub btnAverage_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnAverage.Click
' display the average exam grade
Dim threeGrades As ExamGrades
Dim decAverage As Decimal
Decimal.TryParse(txtGrade1.Text, decExam1)
Decimal.TryParse(txtGrade2.Text, decExam2)
Decimal.TryParse(txtGrade3.Text, decExam3)
decAverage = CalcAverage(threeGrades)
lblResult.Text = decAverage.ToString("N1")
End Sub