windows程序如何调试的问题

刚学 CharlesPetzold的《windows程序设计》，但是不会调试！
每次按F10后，总是在while (GetMessage(&msg,hwnd,0,0)){}这里循环，也不出现什么东西！
请大家帮忙想想办法！小弟不胜感激！举个例子：#include <Windows.h>
#include "SYSMETS.h"
#include <math.h>LRESULT CALLBACK WndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam);int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,PSTR szCmdLine,int iCmdShow)
{
static TCHAR szAppName[]=TEXT("First Program");
MSG msg;
HWND hwnd;
WNDCLASS wndclass; wndclass.style=CS_HREDRAW|CS_VREDRAW;
wndclass.lpfnWndProc=WndProc;
wndclass.cbClsExtra=0;
wndclass.cbWndExtra=0;
wndclass.hInstance=hInstance;
wndclass.hIcon=LoadIcon(NULL,IDI_APPLICATION);
wndclass.hCursor=LoadCursor(NULL,IDC_ARROW);
wndclass.hbrBackground=(HBRUSH)GetStockObject(WHITE_BRUSH);
wndclass.lpszMenuName=NULL;
wndclass.lpszClassName=szAppName; if (!RegisterClass(&wndclass))
{
MessageBox(hwnd,TEXT("Error exists!"),TEXT("Error!"),MB_ICONERROR);
return 0;
} hwnd=CreateWindow(szAppName,TEXT("Hello World!"),WS_OVERLAPPEDWINDOW|WS_HSCROLL|WS_VSCROLL,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,
              CW_USEDEFAULT,NULL,NULL,hInstance,NULL); ShowWindow(hwnd,iCmdShow);
UpdateWindow(hwnd); while (GetMessage(&msg,hwnd,0,0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
} return msg.wParam;
}LRESULT CALLBACK WndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam)
{
static int cxClient,cyClient,cxChar,cyChar,cxCaps,iVscrollPos;
int i,iPaintBeg,iPaintEnd,y;
TCHAR szBuffer[10];
HDC hdc;
PAINTSTRUCT ps;
TEXTMETRIC tm;
SCROLLINFO si; switch(message)
{
case WM_PAINT:
hdc=BeginPaint(hwnd,&ps);
EndPaint(hwnd,&ps);
return 0; case WM_DESTROY:
PostQuitMessage(0);
return 0;
} return DefWindowProc(hwnd,message,wParam,lParam);
}