diff --git a/bigbluebutton_api_python/bigbluebutton.py b/bigbluebutton_api_python/bigbluebutton.py
index 02b31a5..52d79f0 100644
--- a/bigbluebutton_api_python/bigbluebutton.py
+++ b/bigbluebutton_api_python/bigbluebutton.py
@@ -19,14 +19,13 @@
 from jxmlease import parse
 from hashlib import sha1
 if sys.version_info[0] == 2:
-    from urllib import urlencode, urlopen
+    from urllib import urlencode, urlopen, Request
     from urllib import quote
 else:
-    from urllib.request import urlopen
+    from urllib.request import Request, urlopen
     from urllib.parse import urlencode
     from urllib.request import quote
 
-
 class BigBlueButton:
 
     def __init__(self, bbbServerBaseUrl, securitySalt):
@@ -134,7 +133,11 @@ def __send_api_request(self, api_call, params={}, data=None):
         if data is None:
             response = urlopen(url, timeout=10).read()
         else:
-            response = urlopen(url, timeout=10, data=urlencode(data).encode()).read()
+            if isinstance(data, str):
+                request = Request(url, data=bytes(data, "utf8"), headers={'Content-Type': 'application/xml'})
+                response = urlopen(request, timeout=10).read()
+            else:
+                response = urlopen(url, timeout=10, data=urlencode(data).encode()).read()
 
         try:
             rawXml = parse(response)["response"]
diff --git a/bigbluebutton_api_python/parameters/bbbmodule.py b/bigbluebutton_api_python/parameters/bbbmodule.py
index 20df5e2..489503e 100644
--- a/bigbluebutton_api_python/parameters/bbbmodule.py
+++ b/bigbluebutton_api_python/parameters/bbbmodule.py
@@ -14,7 +14,7 @@ def __init__(self):
     def add_slide(self, type, value, name = None):
         if type == self.URL:
             self.__urls.append(value)
-        elif type == self.files:
+        elif type == self.FILE:
             self.__files.append(value)
         elif type == self.base64s:
             self.__base64s.append([name, value])
@@ -45,5 +45,7 @@ def __slides_to_xml(self):
                 with open(single_file, 'r') as f:
                     xml += base64.encodestring(f.read())
                 xml += "</document>"
+        
+        xml += "</module>"
 
-        return xml
\ No newline at end of file
+        return xml