Калькулятор не сохраняет параметры

#include "windows.h"
#include <time.h>
#include <math.h>
#include <string>
#define TIMER 1
#define ID_EDIT 20
#define ID_BUTTON1 1000
#define ID_BUTTON2 5000
#define ID_BUTTON3 1
#define ID_BUTTON4 2
#define ID_BUTTON5 3
#define ID_BUTTON6 4
#define ID_BUTTON7 5
#define ID_BUTTON8 6
#define ID_BUTTON9 7
#define ID_BUTTON10 8
#define ID_BUTTON11 9
#define ID_BUTTON12 10
#define ID_BUTTON13 11
#define ID_BUTTON14 12
#define ID_BUTTON15 13
#define ID_BUTTON16 14
 
#define ID_TEXTBOX1 4000
HINSTANCE hInstance;
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM,LPARAM);
int WINAPI WinMain ( HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR IpCmdLine,int nCmdShow )
{
     
HWND hwnd;//Дескрипторы окон (button - это тоже окна)
HWND button1;
HWND button2;
//HWND button3;
//HWND button4;
//HWND button5;
//HWND button6;
//HWND button7;
//HWND button8;
//HWND button9;
//HWND button10;
//HWND button11;
//HWND button12;
//HWND button13;
//HWND button14;
//HWND button15;
//HWND button16;
//HWND textBo17;
HWND hedit;
MSG msg;
LPARAM lparam;
//static int x,y;
//x=LOWORD (lparam);
        //  y=HIWORD(lparam);
WNDCLASS w;
memset(&w,0,sizeof(WNDCLASS));
w.style=CS_HREDRAW|CS_VREDRAW;
w.lpfnWndProc=WndProc;
w.hInstance=hInstance;
w.hbrBackground=HBRUSH(COLOR_BTNFACE + 1);
w.lpszClassName =L"Super Window";
w.hbrBackground = (HBRUSH) (COLOR_WINDOW + 0);
RegisterClass(&w);
hwnd = CreateWindow(L"Super Window",L"Super Window", WS_OVERLAPPEDWINDOW,
300,500,365,300,NULL,NULL,hInstance,NULL);
// HINSTANCE hInstance;
 
  button1=CreateWindow(L"button",L"+",WS_VISIBLE|WS_CHILD,30,100,50,50,hwnd,(HMENU)ID_BUTTON1,hInstance,NULL);
       button2=CreateWindow(L"button",L"=",WS_VISIBLE|WS_CHILD,110,100,50,50,hwnd,(HMENU)ID_BUTTON2,hInstance,NULL);
       hedit=CreateWindow(L"edit",NULL,WS_CHILD|WS_VISIBLE|WS_BORDER|ES_LEFT,30,50,300,30,hwnd,(HMENU)ID_EDIT,hInstance,NULL);
//textBox=Cr
//POINT point;
//RECT rect;
//GetWindowRect(hwnd,&rect);
//POINT uu;
//GetCursorPos(&point);
//
//uu.x=rect.right/2 + rect.bottom/2;
//uu.y=rect.left/2 + rect.top/2;
////uu.x=rect.top/2;
////uu.y=rect.left/2;
//POINT move;
//move.x=0;
//move.y=0;
//rect.left=point.x-500;
//rect.bottom=point.y-500;
 
 
//GetCursorPos(&point);
//GetWindowPos(
//textBox=CreateWindow(L"koko",L"fdfd",WS_VISIBLE|WS_CHILD,300,205,150,50,hwnd,(HMENU)ID_TEXTBOX1,hInstance,NULL);
 
//SetTimer(hwnd,TIMER,1,NULL);
ShowWindow(hwnd,nCmdShow);
//MoveWindow(hwnd,rect.left,rect.bottom,300,300,true);
while(GetMessage(&msg,NULL,0,0)){
    TranslateMessage(&msg);
    DispatchMessage(&msg);
}
return msg.wParam;
}
 
LRESULT CALLBACK WndProc(HWND hwnd, UINT Message, WPARAM wparam,LPARAM lparam)
{
//HWND hwnd;//Дескрипторы окон (button - это тоже окна)
HWND button1;
HWND button2;
HWND button3;
HWND button4;
HWND button5;
HWND button6;
HWND button7;
HWND button8;
HWND button9;
HWND button10;
HWND button11;
HWND button12;
HWND button13;
HWND button14;
HWND button15;
HWND button16;
//HWND textBo17;
static HWND hedit;
//HINSTANCE hInstance;
 TCHAR str[10];
 char *symbol= new char;
  int *b=new int;
       int *a=new int;
       int *rez=new int;
       int a2;
      
 
      
switch (Message){
   case WM_CREATE:{
       hedit=CreateWindow(L"edit",NULL,WS_CHILD|WS_VISIBLE|WS_BORDER|ES_LEFT,30,50,300,30,hwnd,(HMENU)ID_EDIT,NULL,NULL);
    
       SetFocus(hedit);
      
       
       // return 0;
}
 
      
   case WM_COMMAND:
   if(wparam==ID_BUTTON1){
      // GetWindowText(hwnd,(LPWSTR)str,10);
       SendMessage(hedit,EM_GETLINE,0,(LPARAM)str);
      // SetWindowText(hwnd,L"");
       *a=_wtoi(str);
       SetWindowText(hedit,L"");
       *symbol='+';
       SetFocus(hedit); //return a;
 
     //MessageBox(NULL, L"к",L"Test", MB_OK|MB_ICONEXCLAMATION);
}
   a2=*a;
   if(wparam==ID_BUTTON2){
      // *a=6;
      // *symbol='+';
       SendMessage(hedit,EM_GETLINE,0,(LPARAM)str);
       SetWindowText(hedit,L"");
      * b=_wtoi(str);
       if(*symbol=='+')
           *rez=a2+*b;
       //str="3";
       _itow(*rez,str,10);
     //SendMessage(hedit,WM_PASTE,0,0);
       //AppendWindowText
       
       
       SetWindowText(hedit,(LPCWSTR)str);
       SetFocus(hedit); //return 0;
     //MessageBox(NULL,L" кнопка 2",L"Тест",MB_OK|MB_ICONEXCLAMATION);
}
}
 
 
    if (Message == WM_DESTROY )
{
PostQuitMessage(0);
return 0;
}
return DefWindowProc(hwnd,Message,wparam,lparam);
//return str;
}