this work!.
Code:
void clean_log()
{
	//number of items in the list
int total = LBG_object_getnum(_listbox->item_first,LBG_object_last(_listbox));
	int ping; //for loop
        LBG_LISTITEM* item_old;

	for(ping =0; ping <= total; ping ++)
	{
           item_old = _listbox->item_first->next;           
           LBG_destroy_listitem(_listbox->item_first);
	   _listbox->item_first = item_old;
	}
	
	
}



Please! Use easy words to be translated. because my English is not very good! Grateful.
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