主线程fork两个线程，线程1发消息为何主线程受不到？？代码是。。。。

[wang_bluebird]

//主程序
AfxBeginThread(Thread2,this);
AfxBeginThread(Thread1,this);
//线程1接受数据
while(len != 0)
{
memset(lpszbuf,0,5120);
len=sock.Receive(lpszbuf,5120);
int nLen = p->m_rich.GetTextLength();
p->m_rich.SetSel(nLen,nLen);
p->m_rich.ReplaceSel(lpszbuf);
}
AfxMessageBox("the message has already send");
BOOL IsEnd =false;
SendMessage(p->GetSafeHwnd(),MYME, IsEnd, 1);
//消息响应函数
LRESULT CSevenDlg::OnReceive(WPARAM wParam, LPARAM lParam )
{
BOOL bIsEnd = BOOL(wParam);
AfxEndThread(2);
return 0;
}