Thread: A Problem with DialogBox()

I am having a problem with dialog box. When I call the dialog procedure in the 4th argument, it reports the followig error:

Code:

C:\Program Files\DevStudio\MyProjects1\WhatClr\main.cpp(139) : error C2664: 'DialogBoxParamA' : cannot convert parameter 4 from 'int (void *,unsigned int,unsigned int,long)' to 'int (__stdcall *)(void)'
Error executing cl.exe.

the rest of the code:

Code:

#include <windows.h>
#include "resource.h"
#define ID_TIMER 1
#define ID_EDIT 1

LRESULT CALLBACK WndProc (HWND , UINT, WPARAM, LPARAM);
BOOL CALLBACK AboutDlgProc(HWND, UINT, WPARAM, LPARAM);


int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
					PSTR szCmdLine, int iCmdShow)
{
	static TCHAR szAppName[] = TEXT ("WhatClr");
	HWND hwnd;
	MSG msg;
	WNDCLASS wndc;

	wndc.style          = CS_HREDRAW | CS_VREDRAW;
	wndc.lpfnWndProc    = WndProc;
	wndc.cbClsExtra     = 0;
	wndc.cbWndExtra     = 0;
	wndc.hInstance      = hInstance;
	wndc.hIcon          = LoadIcon (hInstance, szAppName);
	wndc.hCursor        = LoadCursor (hInstance, szAppName);
	wndc.hbrBackground  = (HBRUSH) GetStockObject (WHITE_BRUSH);
	wndc.lpszMenuName   = szAppName;
	wndc.lpszClassName  = szAppName;

	if (!RegisterClass (&wndc))
	{

		MessageBox (NULL, TEXT ("Program Requiers Windows NT"),
			szAppName, MB_ICONERROR);
		return 0;
	}

	


                
	hwnd = CreateWindow (szAppName, TEXT ("Cheappad v0.5"),
		   WS_OVERLAPPEDWINDOW,
		   CW_USEDEFAULT, CW_USEDEFAULT,
		   CW_USEDEFAULT, CW_USEDEFAULT,
		   NULL, NULL, hInstance, NULL) ;

	ShowWindow (hwnd, iCmdShow);
	UpdateWindow (hwnd);

	while (GetMessage (&msg, NULL, 0, 0))
	{
		TranslateMessage (&msg);
		DispatchMessage  (&msg);
	}
	return msg.wParam ;
}


LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{

    
	static HWND hwndEdit;
	int iSelect, iEnable;
	static HINSTANCE hInstance;
	switch (message)
	{

	case WM_CREATE:

		hInstance = ((LPCREATESTRUCT) lParam)->hInstance;
		hwndEdit = CreateWindow (TEXT ("edit"),NULL,
			WS_CHILD | WS_VISIBLE | WS_VSCROLL | WS_BORDER|
			ES_LEFT | ES_MULTILINE|ES_AUTOVSCROLL,
			0,0,0,0,hwnd, (HMENU) ID_EDIT,
			hInstance, NULL);
		return 0;

	case WM_SETFOCUS:
		SetFocus (hwndEdit);
		return 0;

	case WM_SIZE:
		MoveWindow (hwndEdit, 0, 0, LOWORD (lParam), HIWORD (lParam), TRUE);
		return 0;

  case WM_INITMENUPOPUP:

		if (lParam == 1)
		{
			EnableMenuItem ((HMENU) wParam, IDM_EDIT_UNDO,
				SendMessage (hwndEdit, EM_CANUNDO, 0, 0) ?
                       MF_ENABLED : MF_GRAYED);

			
			iSelect = SendMessage (hwndEdit, EM_GETSEL,0,0);


			if (HIWORD (iSelect) == LOWORD (iSelect))
				iEnable = MF_GRAYED;
			else
				iEnable = MF_ENABLED;

			EnableMenuItem ((HMENU) wParam,IDM_EDIT_CUT,iEnable);
			EnableMenuItem ((HMENU) wParam,IDM_EDIT_COPY, iEnable);
			EnableMenuItem ((HMENU) wParam,IDM_EDIT_PASTE, iEnable);

		
			return 0;
		}
		break;

	case WM_COMMAND:

		if (lParam)
		{
			if (LOWORD (lParam) == ID_EDIT &&
				(HIWORD (wParam) == EN_ERRSPACE ||
				HIWORD (wParam) == EN_MAXTEXT))
				MessageBox (hwnd, TEXT ("Cheappad out of space"),
				TEXT ("pop"), MB_OK | MB_ICONSTOP);
			return 0;
		}
		else switch (LOWORD (wParam))
		{
		case IDM_FILE_NEW:
		case IDM_FILE_OPEN:
		case IDM_FILE_SAVE:
		case IDM_FILE_SAVE_AS:
			MessageBeep (0);
			return 0;

		case IDM_APP_EXIT:
			SendMessage (hwnd, WM_CLOSE, 0, 0);
			return 0;

		case IDM_HELP_ABOUT:

			DialogBox (hInstance, TEXT ("AboutBox"), hwnd, AboutDlgProc);
			return 0;
		
			return 0;
		}
	
	case WM_DESTROY:
		
		PostQuitMessage(0);
		return 0;
	}

	return DefWindowProc (hwnd, message, wParam, lParam);
}

BOOL CALLBACK AboutDlgProc(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
	switch (message)
	{
case WM_INITDIALOG:
	return TRUE;

	case WM_COMMAND:
	switch (LOWORD (wParam))
	{
	case IDOK:
	case IDCANCEL:
		EndDialog (hDlg, 0);
		return TRUE;
	}
	break;
	}
	return FALSE;
}

thanks in advance