diff --git a/client.c b/client.c
index 08f02b9..ff24242 100644
--- a/client.c
+++ b/client.c
@@ -133,7 +133,7 @@ int main(int argc, const char *argv[]){
     in_port_t server_port;
     int sock, err;
     if (argc != 4){
-        fprintf(stderr,"invaild arguments number.");
+        fprintf(stderr,"USAUE: %s SERVERNAME PORT FILENAME\n",argv[0]);
         return 1;
     }
     server_name = argv[1];
diff --git a/p-client.c b/p-client.c
index 9d1fc57..c01bc45 100644
--- a/p-client.c
+++ b/p-client.c
@@ -135,7 +135,7 @@ int main(int argc, const char *argv[]){
     in_port_t server_port = 0;
     int sock, err;
     if (argc != 4){
-        fprintf(stderr,"invaild arguments number.");
+        fprintf(stderr,"USAUE: %s SERVERNAME PORT FILENAME\n",argv[0]);
         return 1;
     }
     server_name = argv[1];