void ChangetoDnsNameFormat(unsigned char* dns,unsigned char* host)
{
    int lock = 0 , i;
    strcat((char*)host,".");

    for(i = 0 ; i < strlen((char*)host) ; i++)
    {
        if(host[i]=='.')
        {
            *dns++ = i-lock;
            for(;lock<i;lock++)
            {
                *dns++=host[lock];
            }
            lock++; //or lock=i+1;
        }
    }
    *dns++='\0';
}