-int get_node_from_key(int key);
-int node(int argc, char *argv[]);
-int sender(int argc,char *argv[]);
-void find_successor_node(data_node *my_data, m_task_t join_task);
-finger_elem find_finger_elem(data_node* my_data, int id);
-const char* find_closest_preceding(data_node* n_node, int id); //return a mailbox
-int get_successor_id(m_host_t);
-//need by qsort function
-int compare (const void * a, const void * b)
-{
- return ( *(int*)a - *(int*)b );
-}
+static int node(int argc, char *argv[]);
+static int sender(int argc,char *argv[]);
+static void find_successor_node(data_node *my_data, m_task_t join_task);
+static int find_successor(data_node* my_data, int id);
+static const char* find_closest_preceding(data_node* n_node, int id); //return a mailbox
+static int get_successor_id(m_host_t);