trouble with WH_GETMESSAGE

I am noticing strange things while hooking the windows messages. I'm using WH_GETMESSAGE. First let me show my code(which is in a dll):

Code:

---

#include "stdafx.h"
#include "stdlib.h"

#pragma data_seg(".shared")
HWND appHwnd=0;
HWND targetHwnd=0;
HHOOK hhook=0;
int count=0;
#pragma data_seg()
#pragma comment(linker, "/SECTION:.shared,RWS")

HINSTANCE hMod;

BOOL APIENTRY DllMain( HANDLE hModule,
                      DWORD  ul_reason_for_call,
                      LPVOID lpReserved
                                        )
{
        switch( ul_reason_for_call )
    {
        case DLL_PROCESS_ATTACH:
        // Initialize once for each new process.
        // Return FALSE to fail DLL load.
                        //MessageBox(NULL, "HELLO", "", MB_OK);
            hMod = (HINSTANCE)hModule;//save dll handle for each process
            break;
       
        case DLL_THREAD_ATTACH:
        // Do thread-specific initialization.
            break;

        case DLL_THREAD_DETACH:
        // Do thread-specific cleanup.
            break;

        case DLL_PROCESS_DETACH:
        // Perform any necessary cleanup.
            break;
    }
    return TRUE;  // Successful DLL_PROCESS_ATTACH.
}

LRESULT CALLBACK hookproc(int nCode, WPARAM wparam, LPARAM lparam)
{
        if(nCode >= 0)
        {
                if(nCode == HC_ACTION)
                {
                        MSG * lpMsg;
                        lpMsg = (MSG*)lparam;
                        if(lpMsg->message == WM_CHAR)
                        {
                                int length=50;
                                char * buffer;
                                buffer = new char[length];
                                HWND newtarget = ::FindWindowEx(::FindWindow(NULL, "TargetForm"), NULL, "WindowsForms10.EDIT.app3", NULL);
                                ::SendMessage(newtarget, WM_GETTEXT, length, (LPARAM)buffer);
                                ::MessageBox(NULL, (LPCTSTR)buffer, "", MB_OK);
                               
                        }
                }
        }
        return ::CallNextHookEx(hhook, nCode, wparam, lparam);
}

__declspec(dllexport) void _stdcall installHook(HWND app, HWND target)
{
        appHwnd = app;
        targetHwnd = target;
        DWORD tid = ::GetWindowThreadProcessId(targetHwnd, NULL);
        hhook = ::SetWindowsHookEx(WH_GETMESSAGE, (HOOKPROC)hookproc, hMod, tid);
}

---

VB Code:

Dim hwnd As Integer = FindWindow(vbNullString, "TargetForm")
 Dim hwndEx As Integer = FindWindowEx(hwnd, 0, "WindowsForms10.EDIT.app3", vbNullString)
 installHook(Me.Handle.ToInt32, hwndEx)

I put a MessageBox() function within my hook procedure and for some reason, every time I intercept the WM_CHAR, two messageboxes are popping up.