Sarà una cavolata con .net ma per me è una cosa difficie! grrr

Ho la mia paginetta:
codice:
<%@ Page language="c#" Codebehind="WebForm1.aspx.cs" AutoEventWireup="false" Inherits="upload3.WebForm1" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
	<HEAD>
		<title>WebForm1</title>
	</HEAD>
	<body>
		<form enctype="multipart/form-data" RUNAT="server">
			<div id="Results" runat="server"></div>
			Uploada questo file: <input id="inputFile" type="file" runat="server">

			Nome: <input id="inputNome" type="text" RUNAT="server">
			

			<input type="button" id="BtnUp" value="upload!" OnServerClick="BtnUp_Click" RUNAT="server">
		</form>
	</body>
</HTML
E nel file .aspx ho questo:
codice:
...
		private void BtnUp_Click(object sender, System.EventArgs e)
		{
			inputFile.PostedFile.SaveAs(Server.MapPath(inputNome.Value));
            Results.InnerHtml = "File uplodato su " + inputNome.Value + "
";		
		}
Quando cerco di lanciare la pagina mi esce questo errore:
Compilation Error
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.

Compiler Error Message: CS0122: 'upload3.WebForm1.BtnUp_Click(object, System.EventArgs)' is inaccessible due to its protection level

Source Error:



Line 15: Nome: <input id="inputNome" type="text" RUNAT="server">
Line 16:

Line 17: <input type="button" id="BtnUp" value="upload!" OnServerClick="BtnUp_Click" RUNAT="server">
Line 18: </form>
Line 19: </body>


Source File: http://localhost/upload3/WebForm1.aspx Line: 17