ASP.NET

Private Function IsRobot() As Boolean
     Dim IP As String = Me.Request.UserHostAddress
     Dim key As String = "Contact_" & IP
     Dim obj As Object = Cache(key)
     Dim Counter As Integer = 0
     If obj Is Nothing Then
         Cache.Insert(key, Counter, Nothing, Now.AddMinutes(1), Cache.NoSlidingExpiration)
     Else
         Counter = obj
     End If
     If Counter >= 5 Then
         Me.lblError.Text = "Too many emails"
         Me.lblError.Visible = True
         Return True
     End If
     Cache(key) = Counter + 1
     Return False
 End Function