Win32 cant detect button press

#include<windows.h>
#include"resource.h"

#define IDC_MAIN_EDIT		WM_USER+1
#define IDC_MAIN_BUTTON		WM_USER+2
#define IDC_MAIN_BUTTON2	WM_USER+3

// function prototypes
void InitApp();
LRESULT CALLBACK MainProc(HWND,UINT,WPARAM,LPARAM);
LRESULT CALLBACK OtherProc(HWND,UINT,WPARAM,LPARAM);

// Global variables
HWND hWnd;
HWND other;
HMENU hMenu=NULL;

// Program entry point
int WINAPI WinMain(HINSTANCE hInst,HINSTANCE hPrev,LPSTR line,int CmdShow)
{
	hMenu = LoadMenu(hInst,MAKEINTRESOURCE(IDR_MENU1));
	
	InitApp();

	MSG msg;
	while(GetMessage(&msg,0,0,0))
	{
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}

	return msg.wParam;
}

// initlize application
void InitApp()
{
	WNDCLASS wc;
	wc.cbClsExtra = 0;
	wc.cbWndExtra = 0;
	wc.hbrBackground = (HBRUSH) GetStockObject(LTGRAY_BRUSH);
	wc.hInstance = GetModuleHandle(NULL); //hInst;
	wc.hCursor = LoadCursor(NULL,IDC_ARROW);
	wc.hIcon = LoadIcon(NULL,IDI_APPLICATION);
	wc.lpfnWndProc = (WNDPROC) MainProc;
	wc.lpszClassName = "Main";
	wc.lpszMenuName = NULL; //(LPCSTR)hMenu;
	wc.style = CS_HREDRAW | CS_VREDRAW;

	RegisterClass(&wc);

	wc.lpszClassName = "Other";
	wc.lpfnWndProc = (WNDPROC) OtherProc;
	wc.hbrBackground = (HBRUSH)16;

	RegisterClass(&wc);

	hWnd = CreateWindow("Main","Accounting Application",WS_OVERLAPPEDWINDOW,0,0,170,55,0,hMenu,GetModuleHandle(NULL),0);
	other = CreateWindow("Other","Customer",WS_OVERLAPPEDWINDOW,200,200,640,480,0,0,GetModuleHandle(NULL),0);

	ShowWindow(hWnd,SW_SHOWMAXIMIZED);
	UpdateWindow(hWnd);
}

// Main CallBack Function
LRESULT CALLBACK MainProc(HWND hWnd,UINT msg,WPARAM wParam,LPARAM lParam)
{
	switch(msg)
	{
		case WM_DESTROY:
		{
			PostQuitMessage(0);
		}
		break;
		case WM_CREATE:
		{
		}
		break;
		case WM_COMMAND:
		{
			switch(LOWORD(wParam))
			{
				case ID_FILE_EXIT:
				{
					PostQuitMessage(0);
				} 
				break;
				case ID_MASTERFILES_CUSTOMER:
				{
					ShowWindow(other,SW_SHOW);
				} 
				break;	
			}
		}
		break;
		
		default: return DefWindowProc(hWnd,msg,wParam,lParam);
	}
	return 0;
}

// Other Window CallBack Function
LRESULT CALLBACK OtherProc(HWND hWnd,UINT msg,WPARAM wParam,LPARAM lParam)
{
	switch(msg)
	{
		case WM_CREATE:
		{
			HGDIOBJ hfDefault=GetStockObject(DEFAULT_GUI_FONT);
			HWND hButton=CreateWindowEx(NULL,"BUTTON","OK",WS_TABSTOP|WS_VISIBLE|WS_CHILD|BS_DEFPUSHBUTTON,390,400,100,24,hWnd,(HMENU)IDC_MAIN_BUTTON,GetModuleHandle(NULL),NULL);
			SendMessage(hButton,WM_SETFONT,(WPARAM)hfDefault,MAKELPARAM(FALSE,0));
		}
		break;
		case WM_CLOSE:
		{
			ShowWindow(hWnd,SW_HIDE);
		}
		break;
		case WM_COMMAND:
		{
			switch(LOWORD(wParam))
			{
				case IDC_MAIN_BUTTON:
				{
					MessageBox(NULL,"Button pressed","Information",MB_ICONINFORMATION);
				}
				break;
			}
			break;
		}
		break;

		default: return DefWindowProc(hWnd,msg,wParam,lParam);
	}
	return 0;
}