diff --git a/libs/paylib.py b/libs/paylib.py
index b3c7428..8f522b0 100644
--- a/libs/paylib.py
+++ b/libs/paylib.py
@@ -19,7 +19,7 @@ transport = AIOHTTPTransport(url=node)
 client = Client(transport=transport, fetch_schema_from_transport=True)
 issuer = get_privkey(dunikey, "pubsec").pubkey
 
-def sendGenDoc(recipient, amount, comment):
+def sendGenDoc(recipient, amount, comment=''):
   # TODO: Check args
 
   # Build TX generation document
@@ -52,7 +52,7 @@ def sendGenDoc(recipient, amount, comment):
 
 
 # Check document
-def checkTXDoc(txDoc, recipient, amount, comment):
+def checkTXDoc(txDoc, recipient, amount, comment=''):
   docList = txDoc.splitlines()
   for i, line in enumerate(docList):
     if re.search("Issuers:", line):
@@ -108,4 +108,3 @@ def sendTXDoc(signedDoc):
     sys.stderr.write("Echec de la transaction:\n" + message + "\n")
     sys.exit(1)
 
-    
\ No newline at end of file
diff --git a/pay.py b/pay.py
index 449e12a..1acce79 100755
--- a/pay.py
+++ b/pay.py
@@ -1,8 +1,7 @@
 #!/usr/bin/env python3
 
 import sys
-sys.path.insert(1, 'libs')
-from paylib import *
+from libs.paylib import sendGenDoc, checkTXDoc, signDoc, sendTXDoc
 
 # Get args
 try:
@@ -10,16 +9,14 @@ try:
   amount = int(sys.argv[2])
   if len(sys.argv) > 3:
     comment = sys.argv[3]
-  else:
-    comment = ""
 except Exception as e:
   print("Please enter the recipient's public and the amount\n" + str(e))
   sys.exit(1)
 
 # Execute workflow
 ## Generate TX document from server and check it
-returnGen = sendGenDoc(recipient, amount, comment)
-docIsOK = checkTXDoc(returnGen, recipient, amount, comment)
+returnGen = sendGenDoc(recipient, amount, comment='')
+docIsOK = checkTXDoc(returnGen, recipient, amount, comment='')
 
 # Confirm TX document is ok, sign and send it
 if docIsOK: