I am using Drools. I was using a function to check a condition and I'm facing this problem: When I call the function without using an input argument, then it works fine. However, when I use the function using an argument, then it fails and the program gives the following error: Exception in thread "main" [Error: *unable to resolve method using strict-mode:* rbs.RBS.checkTopology(java.lang.Object)] [Near : {... RBS.checkTopology($alarm.getProper ....}] The rule is: rule "R_LOS" when $alarm:Alarm(properties.get("nativeProbableCause")=="R_LOS",properties.get("perceivedSeverity")!="PS_CLEARED",*/RBS.checkTopology($alarm.getProperties.get("nativeEMSName")/* ) ) then System.out.println($alarm.getProperties().get("perceivedSeverity")); end The function I'm using RBS.checkTopology(String name). Remember, that when I don't pass the argument I change the function prototype too! Kindly, help me out with this!!! -- View this message in context: http://drools.46999.n3.nabble.com/How-to-call-a-function-in-when-statemen... Sent from the Drools: User forum mailing list archive at Nabble.com.