#include?

#define?PROGRAM_NAME	“SIPCLIENT“

void?initialize_pjsua（）;
void?add_transport（）;
void?user_register（）;
void?call_processing（）;
void?make_call（）;
void?add_buddy（）;
void?add_account（）;
void?error_exit（const?char?*error_msg?pj_status_t?action_status）;

static?void?cb_on_incoming_call（pjsua_acc_id?account_id?pjsua_call_id?call_id?pjsip_rx_data?*rdata）;
static?void?cb_on_call_state（pjsua_call_id?call_id?pjsip_event?*e）;
static?void?cb_on_reg_state2（pjsua_acc_id?account_id?pjsua_reg_info?*info）;
static?void?cb_on_buddy_state（pjsua_buddy_id?buddy_id）;

char??????????SIP_SERVER[20];
char??????????USER_NAME[20];
char??????????USER_PASSWORD[20];
pjsua_call_id?call_id_global?=?-1;

/**********************************************************************************************
???????????????????MAIN?FUNCTIONALITY?OF?THE?SIP?CLIENT?PROGRAM?
***********************************************************************************************/
int??main（int?argc?char?*a