[rules-users] Variable Notation in rule Condition

Hi All, I have this doubt regarding the notation used inside the rule's condition. I have a fact HOST having the variables* HostName* and * CPUSockets*. I have the following rule rule "Test" when HOST(HostName!=null, CPUSockets>3) then # do something Is throws an error saying cannot extract field *HostName*. It works fine when i use *hostName*. Can anyone explain me the concept behind this. Thanks in advance :) -- cheers Sumatheja Dasararaju