<form action="uploadfile_validate.php" method="post" enctype="multipart/form-data"> 
   	 <input name="userfile" type="file">
   	 <input name="submit" type="submit" value="Enviar"> 
</form> 

<? 
$nombre_archivo = $_FILES['userfile']['name']; 
if (move_uploaded_file($_FILES['userfile']['tmp_name'], $nombre_archivo)){ 
      echo "Éxito."; 
}else{ 
      echo "Error."; 
}
?> 

Private Sub Main_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        AuthWebBrowser.Navigate("http://__/uploadfile.php")
    End Sub
 
    Private Sub AuthWebBrowser_documentComplete(ByVal pDisp As Object, ByVal URL As Object) Handles AuthWebBrowser.DocumentCompleted
        Static i As Integer
        If i = 0 Then
            With AuthWebBrowser.Document.Forms(0)
                .All("userfile").SetAttribute("value", "C:\usertext.txt")
                .All("submit").Focus()
                My.Computer.Keyboard.SendKeys("{ENTER}")
            End With
        End If
        i = i + 1
    End Sub