'Author:  Eric Heim
'Class:   CS0004

Option Strict On
Option Explicit On
Public Class frmMain

    'If the letter grade radio button is checked, then clear the text boxes, enable the letter grade text box and disable the score text box
    Private Sub rbtLetterGrade_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rbtLetterGrade.CheckedChanged
        If rbtLetterGrade.Checked Then
            txtScore.Text = ""
            txtLetterGrade.Text = ""
            txtLetterGrade.Enabled = True
            txtScore.Enabled = False
        End If
    End Sub

    'If the score radio button is checked, then clear the text boxes, enable the score text box and disable the lett grade text box
    Private Sub rbtScore_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rbtScore.CheckedChanged
        If rbtScore.Checked Then
            txtLetterGrade.Text = ""
            txtScore.Text = ""
            txtScore.Enabled = True
            txtLetterGrade.Enabled = False
        End If
    End Sub

    'OK button click event
    Private Sub btnOK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOK.Click
        'If the letter grade radio button is checked, then switch on the input on the letter grade text box
        If rbtLetterGrade.Checked Then
            Select Case txtLetterGrade.Text
                Case "A", "a"
                    txtScore.Text = "90+"
                Case "B", "b"
                    txtScore.Text = "89-80"
                Case "C", "c"
                    txtScore.Text = "79-70"
                Case "D", "d"
                    txtScore.Text = "69-60"
                Case "F", "f"
                    txtScore.Text = "59 or below"
                Case Else
                    MessageBox.Show("Invalid Letter Grade", "Invalid Letter Grade")
            End Select
            'If the score radio button is checked, then switch on the input on the score text box
        Else
            'If the input for the score text box is not numeric then produce an error
            If Not IsNumeric(txtScore.Text) Then
                MessageBox.Show("The Score Must Be a Number", "The Score Must Be a Number")
            Else
                Select Case CDbl(txtScore.Text)
                    Case 90 To 100
                        txtLetterGrade.Text = "A"
                    Case 80 To 89
                        txtLetterGrade.Text = "B"
                    Case 70 To 79
                        txtLetterGrade.Text = "C"
                    Case 60 To 69
                        txtLetterGrade.Text = "D"
                    Case 0 To 59
                        txtLetterGrade.Text = "F"
                    Case Else
                        MessageBox.Show("Number Out of Valid Range", "Number Out of Valid Range")
                End Select
            End If
        End If
    End Sub
End Class