[uip-users] Some troubles about rs232 to tcp/ip

[uipavr]

  Hi all: void newdata(void){ struct example6_state *s = (struct example6_state 
*)uip_conn->appstate;
 if(s->state == STATE_WAITING) {
   s->state = STATE_HELLO;
   s->dataptr = "hello ";
   s->datalen = 6; }When s->datalen >0,the uip0.9 runs well,But if  s->datalen 
= 0,it does't run well.why?Can someone tell me,thanks!