Scrolling In Webbrowser Control

Imports System.Runtime.InteropServices.Marshal
 Private Shared ScrollVal As Long = 500

    ' Scrollbar direction
    ' All these constents can be found in WinUser.h
    '
    Const SBS_HORZ = 0
    Const SBS_VERT = 1

    ' Windows Messages
    ' All these constents can be found in WinUser.h
    '
    Const WM_VSCROLL = &H115
    Const WM_HSCROLL = &H114
    Const SB_THUMBPOSITION = 4

Public Enum eScrollAction
        Jump = 0
        Relitive = 1
    End Enum

    Public Enum eScrollDirection
        Vertical = 0
        Horizontal = 1
    End Enum

    Private Declare Function GetScrollPos Lib "user32.dll" ( _
            ByVal hWnd As IntPtr, _
            ByVal nBar As Integer) As Integer

    ' API Function: SetScrollPos
    ' Sets ONLY the scrollbar DOES NOT change the control object
    '
    Private Declare Function SetScrollPos Lib "user32.dll" ( _
            ByVal hWnd As IntPtr, _
            ByVal nBar As Integer, _
            ByVal nPos As Integer, _
            ByVal bRedraw As Boolean) As Integer

    ' API Function: PostMessageA
    ' Sends a message to a control (We are going to tell it to synch
    ' with the scrollbar)
    '
    Private Declare Function PostMessageA Lib "user32.dll" ( _
            ByVal hwnd As IntPtr, _
            ByVal wMsg As Integer, _
            ByVal wParam As Integer, _
            ByVal lParam As Integer) As Boolean

Private Sub scrollControl(ByVal hWnd As IntPtr, ByVal Direction As eScrollDirection, ByVal Action As eScrollAction, ByVal Amount As Integer)
       On Error Resume Next
       Dim position As Integer

       ' What direction are we going
       If Direction = eScrollDirection.Horizontal Then

           ' What action are we taking (Jumping or Relative)
           If Action = eScrollAction.Relitive Then
               position = GetScrollPos(hWnd, SBS_HORZ) + Amount
           Else
               position = Amount
           End If

           ' Make it so
           If (SetScrollPos(hWnd, SBS_HORZ, position, True) <> -1) Then
               PostMessageA(hWnd, WM_HSCROLL, SB_THUMBPOSITION + &H10000 * position, Nothing)
           Else
               MsgBox("Can't set info (Err: " & GetLastWin32Error() & ")")
           End If

       Else

           ' What action are we taking (Jumping or Relative)
           If Action = eScrollAction.Relitive Then
               position = GetScrollPos(hWnd, SBS_VERT) + Amount
           Else
               position = Amount
           End If

           ' Make it so
           If (SetScrollPos(hWnd, SBS_VERT, position, True) <> -1) Then
               PostMessageA(hWnd, WM_VSCROLL, SB_THUMBPOSITION + &H10000 * position, Nothing)
           Else
               MsgBox("Can't set info (Err: " & GetLastWin32Error() & ")")
           End If
       End If
   End Sub

scrollControl(control.Handle, eScrollDirection.Vertical, eScrollAction.Jump, ScrollVal)