显示成绩等级...

Public Class Form1

    Private Sub Button1_Click(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles Button1.Click
        Dim i As Integer
        i = Val(InputBox("请输入学习成绩:"))
        If i >= 100 Or i <= 0 Then
            MsgBox("成绩应该在0～100之间!",vbCritical)
        ElseIf i >= 90 Then
            TextBox1.Text = "优秀"
        ElseIf i >= 75 Then
            TextBox1.Text = "良好"
        ElseIf i >= 60 Then
            TextBox1.Text = "及格"
        Else
            TextBox1.Text = "不及格"
        End If
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub
End Class