Thread: Unexpected Output, modal window!

Hi all, I am new to Windows programming. I am trying to make a modal window from a main window on press of a button. The main window should be disabled and the modal window should be enabled, but instead I end up getting both the windows disabled in my output. Here's the code:

Code:

#include<windows.h>

LRESULT CALLBACK WndProc      (HWND, UINT, WPARAM, LPARAM) ;
LRESULT CALLBACK ChildWndProc (HWND, UINT, WPARAM, LPARAM) ;   //Child window procedure//

#define ID_BUTTON1 1
int CreateChildWindow(HINSTANCE, HWND);                        //Funtion to create child window//

//global variables
static MSG msg1;
HWND b1,childHwnd;
static TCHAR chappname[]= TEXT("Child");
WNDCLASS child_window;
static HINSTANCE ChildInstance;
HWND hwnd;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,PSTR szCmdLine, int iCmdShow)
{
	static TCHAR szAppName[] = TEXT ("Modal_Window") ;
	MSG msg ;
    WNDCLASS wndclass ;
    wndclass.style         = CS_HREDRAW | CS_VREDRAW ;
    wndclass.lpfnWndProc   = WndProc ;
    wndclass.cbClsExtra    = 0 ;
    wndclass.cbWndExtra    = 0 ;
    wndclass.hInstance     = hInstance ;
    wndclass.hIcon         = LoadIcon (hInstance, szAppName) ;   	 
    wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW) ;
  	wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
	wndclass.lpszMenuName  = szAppName ;
	wndclass.lpszClassName = szAppName ;
     
    if (!RegisterClass (&wndclass))
    {
          MessageBox (NULL, TEXT ("This program requires Windows NT!"),
                      szAppName, MB_ICONERROR) ;
          return 0 ;
     }
     
     hwnd=CreateWindow (szAppName, TEXT ("About Modal Window"),
                          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 HINSTANCE hInstance ;
	
     switch (message)
     {
	 case WM_CREATE : b1=CreateWindow(TEXT("Button"),TEXT("Button1"),WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON,10,20,50,30,hwnd,(HMENU) ID_BUTTON1,hInstance,0);
		              return 0 ;
          
     case WM_COMMAND : 
		      {
			    switch(LOWORD(wParam))
			    {
		   	      case ID_BUTTON1: CreateChildWindow(ChildInstance,hwnd);
				                   break;
				  default : break;
			    }
              return 0 ;
		     }
     case WM_DESTROY : PostQuitMessage (0) ;
			          return 0; 
	 }  //switch close
     return DefWindowProc (hwnd, message, wParam, lParam) ;
}

int CreateChildWindow(HINSTANCE ChildInstance, HWND hwnd)
{
	//int error,i;
	child_window.style         = CS_HREDRAW | CS_VREDRAW ;
	child_window.lpfnWndProc   = ChildWndProc ;
	child_window.cbClsExtra    = 0 ;
	child_window.cbWndExtra    = 0 ;
	child_window.hInstance     = ChildInstance ;
	child_window.hIcon         = LoadIcon (NULL, IDI_APPLICATION) ;
	child_window.hCursor       = LoadCursor (NULL, IDC_ARROW) ;
	child_window.hbrBackground = (HBRUSH) GetStockObject (BLACK_BRUSH) ;
	child_window.lpszMenuName  = NULL;
	child_window.lpszClassName = chappname;
	
	if (!RegisterClass (&child_window))
    {
		MessageBox (hwnd, TEXT ("This program requires Windows NT!"), chappname, MB_ICONERROR) ;       //Problem here!//
						  
		return -1;
	}
			
	// CreateChildWindow(ChildInstance,hwnd);
        childHwnd = CreateWindow (chappname, TEXT ("child Modal Window"),      
		  WS_OVERLAPPEDWINDOW | WS_VISIBLE,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                         600, 600,
                          hwnd, NULL,ChildInstance , NULL) ;

	 //error = GetLastError ();
	 
	 EnableWindow(hwnd,FALSE);               //disable main window
	  return 0;
}  

LRESULT CALLBACK ChildWndProc(HWND childHwnd,UINT message,WPARAM wParam,LPARAM lParam)
{
	switch(message)
	{
	case WM_CREATE: break;
	case WM_PAINT: break;
	case WM_DESTROY :PostQuitMessage (0) ;
			            EnableWindow(hwnd,TRUE);
                                    return 0;
	default: break;
	}
	return DefWindowProc(childHwnd, message, wParam, lParam) ;
}

I tried again and what I found is that my child window is constrained inside the main window.. so when my main window is disabled the child becomes disabled. I can't find how to remove this so that my child window can move outside my main window as well.

Well, I have removed this problem too.. Now the only issue is that when I close my modal window to enable the main window again and press the button to again create the modal window, I am unable to register it.. Code has been edited to show the changes done.

Any suggestions would be greatly appreciated! Please reply!