switch(message)
{
case WM_CREATE:
     hInstance=((LPCREATESTRUCT)lParam->hInstance);
     return 0;
case WM_COMMAND:
     switch((LOWORD)wParam)
     {
      case IDM_HELP_ABOUT:
DialogBox(hInstance,TEXT("ABOUTBOX"),hwnd,DialogProc);
break;
     }
      return 0;
      case WM_DESTROY:          //为什么敲这行的时候它不自动与
//case WM_COMMAND:对齐?偏要与case IDM_HELP_ABOUT:同列?