what is the error in my .net2003 windows application mouse move programme?

Imports System
Imports System.Windows.Forms
Imports System.Runtime.InteropServices
 
Public Class mouseclickprogramme
    Inherits System.Windows.Forms.Form
 
    <DllImport("user32.dll", CharSet:=CharSet.Auto, CallingConvention:=CallingConvention.StdCall)> _
        Public Shared Sub mouse_event(ByVal dwFlags As Long, ByVal dx As Long, ByVal dy As Long, ByVal cButtons As Long, ByVal dwExtraInfo As Long)
    End Sub
 
    Private Const MOUSEEVENTF_LEFTDOWN As Integer = &H2
    Private Const MOUSEEVENTF_LEFTUP As Integer = &H4
    Private Const MOUSEEVENTF_RIGHTDOWN As Integer = &H8
    Private Const MOUSEEVENTF_RIGHTUP As Integer = &H10
 
    Public Sub DoMouseClick()
        'Call the imported function with the cursor's current position
        Dim X As Integer = Cursor.Position.X
        Dim Y As Integer = Cursor.Position.Y
        mouse_event(MOUSEEVENTF_LEFTDOWN Or MOUSEEVENTF_LEFTUP, X, Y, 0, 0)
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
        DoMouseClick()
    End Sub
 
    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        MsgBox("ok")
    End Sub
 
 consider the above commands. I run the programme. no one reaction I found. 
i put the following line that place(70,20) has a command button3 but  no one reaction i found 
 mouse_event(MOUSEEVENTF_LEFTDOWN Or MOUSEEVENTF_LEFTUP, 70,20, 0, 0)