Visual C++ :: Error In Registering Windows Class

The following code it taken from msdn library but it is failing to compile.

the following code has a header where all the variables used here are stored in header App.h.

The following lines are giving trouble:

Code:
DialogBox(pApp->getInstance(), MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, pApp->About);
error: 'App::About': function call missing argument list; use '&App::About' to create a pointer to member

Code:
wcex.lpfnWndProc= &App::WndProc;
error: '=' : cannot convert from 'LRESULT (__stdcall App::* )(HWND,UINT,WPARAM,LPARAM)' to 'WNDPROC'

There is no context in which this conversion is possible

Here is the complete code:

#include "stdafx.h"
#include "App.h"
App::App(void) {
}
App::~App(void) {

[Code] .....