diff --git a/client/netwrapper.py b/client/netwrapper.py
index 4e19384..4802faf 100644
--- a/client/netwrapper.py
+++ b/client/netwrapper.py
@@ -13,7 +13,7 @@ from netsim import network_interface
 
 
 class NetWrapper:
-    def __init__(self, privateKey: RsaKey, clientAddress: str, username: str, serverPubKey: RsaKey,
+    def __init__(self, privateKey: RsaKey, clientAddress: str, serverPubKey: RsaKey, username: str = "",
                  serverAddr: str = 'A'):
         self.network = network_interface('./../../netsim/network/', clientAddress)
         self.serverAddr = serverAddr
@@ -105,6 +105,10 @@ class NetWrapper:
             print("Authentication error")
 
     def connectToServer(self, password: str) -> None:
+        if self.username == "":
+            raise Exception('Username is not initialized')
+        if password == "":
+            raise Exception('Passowrd may not be empty')
         identStatus = self.identifyServer()
         if not identStatus:
             raise Exception('Server identification faliure')