CLIENT WINDOW + SOCKET [SANS MFC]

#include <windows.h>
#include "resource.h"
#include <winsock.h>
#pragma comment(lib,"wsock32.lib")

BOOL CALLBACK IpDialogFunc(HWND hdlg, UINT mssg, WPARAM wParam,LPARAM lParam) 
{
  switch(mssg) {
    case WM_COMMAND:
      switch(wParam) {
        case IDC_BUTTON1:
        case ID_FILE_EXIT:
          PostMessage(hdlg, WM_COMMAND, IDCANCEL, 0);
          return 0;
        case 1234:
			/*on ouvre le dialog 
          pour la connection du socket
		  */
		  DialogBox(0,MAKEINTRESOURCE(IDD_DIALOG2), hdlg, IpDialogFunc);
          return 0;
        case exit_ :
              MessageBox(0,"Creer par Creatix(ZzZzZz)","Createur ...",0);
PostQuitMessage(0);          
              return 0;
        case about :
        MessageBox(0,"Creer par Creatix(ZzZzZz)","Createur ...",0);
        return 0;
        case IDCANCEL :
          EndDialog(hdlg, 0);
		case envoyer :
// permet de stocker l'ip dans string
char *string;
string = (char *)malloc(GetWindowTextLength(GetDlgItem(hdlg,IDC_EDIT2))+1);
(char *)GetWindowText(GetDlgItem(hdlg,IDC_EDIT2),string,GetWindowTextLength(GetDlgItem(hdlg,IDC_EDIT2))+1);
// permet de stocker la commande dans string2
char *string2;
string2 = (char *)malloc(GetWindowTextLength(GetDlgItem(hdlg,IDC_EDIT1))+1);
(char *)GetWindowText(GetDlgItem(hdlg,IDC_EDIT1),string2,GetWindowTextLength(GetDlgItem(hdlg,IDC_EDIT1))+1);

//initialisation du socket
WSADATA wsadata;
WSAStartup(MAKEWORD(1,0),&wsadata);
SOCKET sock = socket(AF_INET,SOCK_STREAM,0);
SOCKADDR_IN sin;

//l'ip ou le socket va se connecter
sin.sin_addr.s_addr = inet_addr(string);
//la famille du socket
sin.sin_family = AF_INET;
//le port que vous pouvez changer
sin.sin_port  = htons(21452);
//on connect le socket
connect(sock,(LPSOCKADDR)&sin,sizeof(sin));
//on send string2
send(sock,string2,sizeof(string2),0);
//on close le socket et on libre la memoire
closesocket(sock);
WSACleanup();
free(string);
return 0;
					   }
      return 0;
  }
  return 0;
}
/*fonction WinMain principale
c'est elle qui ets executer en premier
*/
int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nCmdShow) 
{
	//on ouvre le dialog (qui ets en fait la 
	//fenetre principale
  DialogBox(0,MAKEINTRESOURCE(IDD_APP), 0, IpDialogFunc);
  return 0;
}