diff --git a/includes/doubleFilter.py b/includes/doubleFilter.py
new file mode 100644
index 0000000..321dd6f
--- /dev/null
+++ b/includes/doubleFilter.py
@@ -0,0 +1,56 @@
+#!/usr/bin/python
+# -*- coding: cp1252 -*-
+
+"""
+doubleFilter is the central function to filter out double alarms.
+You can set the number of historical entries the filter will check
+and the time ignoring the id in case of a double alarm
+
+@author: Jens Herrmann
+
+@requires: Configuration has to be set in the config.ini
+"""
+
+import logging # Global logger
+import time    # timestamp for doublealarm
+
+from includes import globals  # Global variables
+
+#
+# ListStructure [0..n] = (ID, TimeStamp)
+#
+
+def checkID(typ, id):
+	"""
+	check if id was called in the last x sec and n entries
+	
+	@requires:  Configuration has to be set in the config.ini
+	
+	@return:    True if check was OK
+	@return:    False if double was found
+	"""
+	timestamp = int(time.time()) # Get Timestamp 
+
+	for i in range(len(globals.doubleList)):
+		(xID, xTimestamp) = globals.doubleList[i]
+		# given ID found?
+		# return False if the first entry in double_ignore_time is found, we will not check for younger one...
+		if id == xID and timestamp < xTimestamp + globals.config.getint("BOSWatch", "double_ignore_time"):
+			logging.info("%s double alarm: %s within %s second(s)", typ, xID, timestamp-xTimestamp)
+			return False
+	return True
+	
+
+def newEntry(id):
+	"""
+	new entry in double alarm
+	
+	@return:    nothing
+	"""
+	timestamp = int(time.time()) # Get Timestamp 
+	globals.doubleList.append((id, timestamp))
+	
+	# now check if list has more than n entries:
+	if len(globals.doubleList) > 10:
+		# we have to kill the oldest one
+		globals.doubleList.pop(0)	
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