diff --git a/src/data/download_using_xapi.py b/src/data/download_using_xapi.py
index 6fe3fe9..337646b 100644
--- a/src/data/download_using_xapi.py
+++ b/src/data/download_using_xapi.py
@@ -5,75 +5,88 @@
 
 def xapidownload():
 	try:
-		# get the input XAPI url
-		#
-		in_xapi_url = arcpy.GetParameterAsText(0)
-
-		# get the request extent
-		#
-		request_extent = arcpy.GetParameterAsText(1)
-		AddMsgAndPrint(request_extent)
-
-		# if no extent was set and the default is passed in  -- meaning "#" then set an empty string
+		# 1. get the input XAPI url : in_xapi_url
+		# 1. Récupération de l'URL du serveur XAPI : in_xapi_url
+		in_xapi_url = str(arcpy.GetParameterAsText(0))
+		AddMsgAndPrint('1. Distant serveur URL : ' + in_xapi_url)
+
+		# 2. get the request extent : request_extent
+		# 2. Récupération de l'option de l'emprise : request_extent
+		request_extent = str(arcpy.GetParameterAsText(1))
+		AddMsgAndPrint('2. Extent option : ' + request_extent)
+
+		# 3. if no extent was set and the default is passed in  -- meaning "#" then set an empty string
+		# 3. Récupération de l'emprise de la requête : request_extent
+		# Si l'emprise n'a pas été spécifiée ou que l'option "emprise par défaut" est choisie (c'est à dire "#"),
+		# alors la valeur est une chaine de caractères vide
 		if (request_extent == '#'):
 			request_extent = ''
+			AddMsgAndPrint('3.1. Empty extent : ' + request_extent)
 		elif (request_extent == 'DEFAULT'):
 			request_extent = ''
+			AddMsgAndPrint('3.2. Default extent : ' + request_extent)
 		else:
 			coordinates = request_extent.split(' ')
 			request_extent = str(locale.atof(coordinates[0])) + ',' +  str(locale.atof(coordinates[1])) + ',' + str(locale.atof(coordinates[2])) + ',' + str(locale.atof(coordinates[3]))
+			AddMsgAndPrint('3.3.1 Extent: ' + request_extent)
 			request_extent = CheckForBrackets('bbox=' + request_extent)
+			AddMsgAndPrint('3.3.2 Extent request : ' + request_extent)
 			request_extent = urllib.quote_plus(request_extent)
+			AddMsgAndPrint('3.3.3 URL Lib : ' + request_extent)
 
-		# get the type setting
+		# 4. get the type setting : request_type
 		# this can one of the following parameters
-		# * - meaning all
-		# node
-		# way
-		# relation
-		#
-		request_type = arcpy.GetParameterAsText(2)
+		# 4. Récupération des paramètres types : request_type
+		# 	Les valeurs des paramètres peuvent être :
+		# * - meaning all (tous)
+		# 	node (noeuds)
+		# 	way (lignes)
+		# 	relation (relations)
+		request_type = str(arcpy.GetParameterAsText(2))
+		AddMsgAndPrint('4. Request type : ' + request_type)
 		#request_type = urllib.quote(request_type)
 
-		# get the predicate string
-		#
-		request_predicate = arcpy.GetParameterAsText(3)
+		# 5. get the predicate string : request_predicate
+		# 5. Récupération de la chaine de prédicat : request_predicate
+		request_predicate = str(arcpy.GetParameterAsText(3))
 		if (len(request_predicate) != 0):
 			request_predicate = CheckForBrackets(request_predicate)
 			request_predicate = urllib.quote(request_predicate)
+			AddMsgAndPrint('5. Predicate : ' + request_predicate)
 
-		# get the location for the downloaded file
-		#
+		# 6. get the location for the downloaded file : xapi_osm_file
+		# 6. Récupération de l'adresse du fichier téléchargé : xapi_osm_file
 		xapi_osm_file = arcpy.GetParameterAsText(4)
 
-		# assemble the request url
+		# 7. assemble the request url
 		# sample: http://jxapi.openstreetmap.org/xapi/api/0.6/*%5Bname=Sylt%5D
-		#
+		# 7. Assemble la requête url
 		request_url = in_xapi_url + request_type + request_predicate + request_extent
-		AddMsgAndPrint(request_url)
+		AddMsgAndPrint('7. Request URL : ' + request_url)
 
-		# issue the request against the XAPI endpoint
-		#
+		# 8. issue the request against the XAPI endpoint
+		# 8. Emission de la requête avec les critères XAPI
 		try:
 			xapi_response = urllib2.urlopen(request_url)
 		except urllib2.URLError, e:
 			if hasattr(e, 'reason'):
-				AddMsgAndPrint('Unable to reach the server.', 2)
+				AddMsgAndPrint('8.1. Unable to reach the server.', 2)
 				AddMsgAndPrint(e.reason, 2)
 			elif hasattr(e, 'code'):
-				AddMsgAndPrint('The server was unable to fulfill the request.', 2)
+				AddMsgAndPrint('8.2. The server was unable to fulfill the request.', 2)
 				AddMsgAndPrint(e.code, 2)
 
 		else:
 			# write the content into a file on disk
-			#
+			# Ecrit le contenu de la requête dans un fichier sur le disque
 			with open(xapi_osm_file,'w') as xapifile:
 				xapifile.write(xapi_response.read())
 
 	except Exception as err:
-		AddMsgAndPrint(err.message, 2)
-
+		AddMsgAndPrint('99. Error ' + err.message, 2)
 
+	# 9. Check for brackets
+	# 9. Vérification de la présence des crochets
 def CheckForBrackets(inputString):
 	paddedString = inputString
 
@@ -87,17 +100,20 @@ def CheckForBrackets(inputString):
 
 
 def AddMsgAndPrint(msg, severity=0):
-    # Adds a Message (in case this is run as a tool)
+    # 10. Adds a Message (in case this is run as a tool)
     # and also prints the message to the screen (standard output)
-    #
+    # 10. Ajoute un message dans le cas où le script est lancé comme outil
+    # et affiche aussi le message à l'écran (sortie standard)
     print msg
 
-    # Split the message on \n first, so that if it's multiple lines,
+    # 11. Split the message on \n first, so that if it's multiple lines,
     #  a GPMessage will be added for each line
+    # 11. Coupe le message sur le premier \n pour que, en cas de message multi-lignes, 
+    # un message GP soit ajouté à chaque ligne
     try:
         for string in msg.split('\n'):
             # Add appropriate geoprocessing message
-            #
+            # Ajoute le message de géoprocess approprié
             if severity == 0:
                 arcpy.AddMessage(string)
             elif severity == 1:
@@ -109,4 +125,3 @@ def AddMsgAndPrint(msg, severity=0):
 
 if __name__ == '__main__':
     xapidownload()
-