#include <wvstream.h>void mycallback(WvStream &s, void *userdata){    WvStream *outstream = (WvStream *)userdata;        char *str = s.getline(0);    if (str)	outstream->print("You said: %s\n", str);}int main(){    wvcon->setcallback(mycallback, wvcon);    while (wvcon->isok())    {	if (wvcon->select(-1))	    wvcon->callback();    }}