help

This is a homework assignment i am currently working on:

Write a program to analyze a list of grades to determine the number of A's, B's, C's, etc. after applying a curve percentage selected by the user. When the form loads it should contain all the grades and available curves in the list boxes on the left. The user selects a curve and clicks the "Apply Curve" button. The program should display the curved grades (based upon the selected curve) and the grade distribution in the list boxes on the right:
[IMG]http://tinypic.com/r/14j89c4/5[/IMG]
[IMG][IMG]http://i41.tinypic.com/14j89c4.png[/IMG][/IMG]
Heres what i have so far:

  Dim A, B, C, D, F As Integer
        A = 0
        B = 0
        C = 0
        D = 0
        F = 0

        For i As Integer = 0 To lstGrade.Items.Count - 1
            Dim Grade As Integer = CInt(lstGrade.Items(i))
            If Grade >= 90 Then
                A += 1
            Else
                If Grade >= 80 Then
                    B += 1
                Else
                    If Grade >= 70 Then
                        C += 1
                    Else
                        If Grade >= 65 Then
                            D += 1
                        Else
                            F += 1
                        End If
                    End If
                End If
            End If
        Next
        lstGradeDistribution.Items.Clear()
        lstGradeDistribution.Items.Add("A: " & A.ToString)
        lstGradeDistribution.Items.Add("B: " & B.ToString)
        lstGradeDistribution.Items.Add("C: " & C.ToString)
        lstGradeDistribution.Items.Add("D: " & D.ToString)
        lstGradeDistribution.Items.Add("F: " & F.ToString)



    End Sub

i need help setting the curves. i have no idea how to.

Who uses VB anymore?