newbie want to compile example

[Gloria Saripah Patara]

hello, i'm glowz. a newbie here. i want to ask something to you all about dbus.
i've tried the first example program like inside the tutorial. i can
compile the program without warning and error message. i compile it
with this command:

gcc -ldbus-1 -ldbus-glib-1 -lglib-2.0 -I/usr/local/include/dbus-1.0
-I/usr/local/lib/dbus-1.0/include -I/usr/include/glib-2.0
-I/usr/lib/glib-2.0/include -o coba coba1.c
-DDBUS_API_SUBJECT_TO_CHANGE

And then, i attempt to run it. however, it goes to give me an error
that i can't understand,  like this:

Failed to open connection to bus: Unable to determine the address of
the message bus (try 'man dbus-launch' and 'man dbus-daemon' for help)

Here's the code :
----------------------------------------------------------------------------------------------------
#include <dbus/dbus.h>
#include <dbus/dbus-glib.h>
#include <dbus/dbus-glib-lowlevel.h>

int main (int argc, char **argv)
{
	DBusGConnection *connection;
  	GError *error;
  	DBusGProxy *proxy;
  	char **name_list;
  	char **name_list_ptr;

  	g_type_init ();

  	error = NULL;
  	connection = dbus_g_bus_get (DBUS_BUS_SESSION, &error);
  	if (connection == NULL){
   	g_printerr ("Failed to open connection to bus: %s\n",error->message);
      g_error_free (error);
      exit (1);
	}

  	/* Create a proxy object for the "bus driver" (name
"org.freedesktop.DBus") */
  	proxy = dbus_g_proxy_new_for_name (connection,
                                     DBUS_SERVICE_DBUS,
                                     DBUS_PATH_DBUS,
                                     DBUS_INTERFACE_DBUS);

  	/* Call ListNames method, wait for reply */
  	error = NULL;
  	if (!dbus_g_proxy_call (proxy, "ListNames", &error, G_TYPE_INVALID,
                          G_TYPE_STRV, &name_list, G_TYPE_INVALID)){
      /* Just do demonstrate remote exceptions versus regular GError */
      if (error->domain == DBUS_GERROR && error->code ==
DBUS_GERROR_REMOTE_EXCEPTION)
      	g_printerr ("Caught remote method exception %s:
%s",dbus_g_error_get_name (error),error->message);
      else
        g_printerr ("Error: %s\n", error->message);
      g_error_free (error);
      exit (1);
    }

  	/* Print the results */
  	g_print ("Names on the message bus:\n");

  	for (name_list_ptr = name_list; *name_list_ptr; name_list_ptr++){
   	g_print ("  %s\n", *name_list_ptr);
   }
  	
  	g_strfreev (name_list);
  	g_object_unref (proxy);

  	return 0;
}
------------------------------------------------------------------------------------------------------

Your considerations will help me.
------------------------
Thanks in advance!