高手帮忙，在sdk对话框中显示一幅位图

我想在SDK对话框中显示一幅位图，对话框可以显示出来，位图却显示不出来！以下是代码，高手帮忙看看啊！！！
#include <windows.h>
#include "resource.h"HINSTANCE hInst;BOOL FAR PASCAL ProcMain(HWND hDlg,UINT message,WPARAM wParam,LPARAM lParam)
{ switch(message)
{
case WM_INITDIALOG:
break;
case WM_ERASEBKGND:
HDC hDC,hMDC;
HBITMAP bmp;
HGDIOBJ oldbmp; hDC=GetDC(hDlg);
        bmp=LoadBitmap(NULL,MAKEINTRESOURCE(IDB_BITMAP1));
hMDC=CreateCompatibleDC(hDC);
oldbmp=SelectObject(hMDC,&bmp);
BitBlt(hDC,0,0,240,149,hMDC,0,0,SRCAND);
SelectObject(hMDC,oldbmp);
ReleaseDC(hDlg,hDC);
DeleteDC(hMDC);
  DeleteObject(bmp);
break;
case WM_COMMAND:
if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL) 
{
EndDialog(hDlg, LOWORD(wParam));
return TRUE;
}
break;
case WM_CLOSE:
PostQuitMessage(0);
break;
default:
return FALSE; }return TRUE;
}int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nShowCmd)
{
hInst=hInstance;
DialogBoxParam(hInstance,MAKEINTRESOURCE(IDD_DIALOG1),NULL,(DLGPROC)ProcMain,0);
return 0;
}