Public Class Form1

  '//////////////CREATED BY ZEKI OZYILMAZ for CST112

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        'Calculates what years are leap years accordin to the gregorian calendar
        'Step0. Declarations
        Dim year, leapyear As Integer

        'Step1. Input
        year = Val(TextBox1.Text)
        'Step2. Process
        If year / 400 =  Then
        ElseIf year / 100 Then
        ElseIf year / 4 Then

        End If


        'Step3. Output
        If leapyear Then
            ListBox1.Items.Add(year & " is a leap year.")
        Else
            ListBox1.Items.Add(year & " is not a leap year.")
        End If

    End Sub
End Class