ObjClassForm1

Public Class Form1
    Private Sub btnConvertUpper_Click(sender As Object, e As EventArgs) Handles btnConvertUpper.Click
        Dim NewCode As String
        Dim objConvertCode = New ClassConvert
        objConvertCode = New ClassConvert
        NewCode = objConvertCode.ConvertUpperCase(txt1.Text)
        txt1.Text = NewCode
    End Sub

    Private Sub btnConvertLower_Click(sender As Object, e As EventArgs) Handles btnConvertLower.Click
        Dim NewCode As String
        Dim objConvertCode = New ClassConvert
        objConvertCode = New ClassConvert
        NewCode = objConvertCode.ConvertLowerCase(txt1.Text)
        txt1.Text = NewCode
    End Sub
End Class