Public Class Form1
    Public Structure Struct_INTERNET_PROXY_INFO
        Public dwAccessType As Integer
        Public proxy As IntPtr
        Public proxyBypass As IntPtr
    End Structure
#Region "Proxy"
 
    ' The Windows API function that allows us to manipulate
    ' IE settings programmatically.
    Private Declare Auto Function InternetSetOption Lib "wininet.dll" _
    (ByVal hInternet As IntPtr, ByVal dwOption As Integer, ByVal lpBuffer As _
    IntPtr, _
     ByVal lpdwBufferLength As Integer) As Boolean
 
    ' The function we will be using to set the proxy settings.
    Private Sub RefreshIESettings(ByVal strProxy As String)
        Const INTERNET_OPTION_PROXY As Integer = 38
        Const INTERNET_OPEN_TYPE_PROXY As Integer = 3
        Dim struct_IPI As Struct_INTERNET_PROXY_INFO
 
        ' Filling in structure
        struct_IPI.dwAccessType = INTERNET_OPEN_TYPE_PROXY
        struct_IPI.proxy = _
          System.Runtime.InteropServices.Marshal.StringToHGlobalAnsi(strProxy)
        struct_IPI.proxyBypass = _
        System.Runtime.InteropServices.Marshal.StringToHGlobalAnsi("local")
 
        ' Allocating memory
        Dim intptrStruct As IntPtr = _
          System.Runtime.InteropServices.Marshal.AllocCoTaskMem( _
          System.Runtime.InteropServices.Marshal.SizeOf(struct_IPI))
 
        ' Converting structure to IntPtr
        System.Runtime.InteropServices.Marshal.StructureToPtr(struct_IPI, _
          intptrStruct, True)
        Dim iReturn As Boolean = InternetSetOption(IntPtr.Zero, _
        INTERNET_OPTION_PROXY, intptrStruct, _
        System.Runtime.InteropServices.Marshal.SizeOf(struct_IPI))
    End Sub
 
#End Region
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button2.Click
        WebBrowser1.GoForward()
    End Sub
 
    Private Sub WebBrowser1_DocumentCompleted(ByVal sender As System.Object, _
      ByVal e As System.Windows.Forms.WebBrowserDocumentCompletedEventArgs) _
      Handles WebBrowser1.DocumentCompleted
 
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        WebBrowser1.GoBack()
    End Sub
 
    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button3.Click
        WebBrowser1.Navigate(TextBox1.Text)
    End Sub
 
    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button4.Click
        WebBrowser1.Navigate("http://www.google.de")
    End Sub
 
    Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button5.Click
        WebBrowser1.Navigate("http://www.hydrox-net.de/proxy.html")
    End Sub
 
    Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs)
        Me.Close()
    End Sub
End Class