how to use the MACROs?

[ww]

i am puzzled by the macros used in the source code of kannel just like the difinition of the MSG and the State-machine   here is the source code in the wtls_state-decl.h  ROW(CREATING,     SEC_Exception_Req,     1,     {             info(0,"----------------begin a new 12 machine-----------");             /* Send off a T_Unitdata_Req containing an exception as specified */             send_alert(event->u.SEC_Exception_Req.alert_level,                        event->u.SEC_Exception_Req.alert_desc, wtls_machine);     },     CREATING)     the source code in the wtls.c   if(event->type == T_Unitdata_Ind)  { if( wtls_machine->encrypted )  {  info(0, "lyl: start pdu list ");  wtls_decrypt_pdu_list(wtls_machine, event->u.T_Unitdata_Ind.pdu_list);  }  info(0, "lyl: end pdu list ");  du_list);  } #define STATE_NAME(state)      #define ROW(wtls_state, event_type, condition, action, next_state) \              if (wtls_machine->state == wtls_state && \                 event->type == event_type && \                 (condition)) { \                 action \                 wtls_machine->state = next_state; \                 debug("wap.wtls", 0, "WTLS %ld: New state %s", wtls_machine->mid , #next_state); \              } else      #include "wtls_state-decl.h"              {                 error(0, "WTLS: handle_event: unhandled event!");                 debug("wap.wtls",0, "lyl: event->type = %d", event->type);                 wap_event_destroy(event);                 return;              }   i want to know how to use and run it ,please help me :)