Hi Mark
Thank for your reply.

When i tried with the rule file(.drl format) then also i faced the same problem.
Actually the problem is that when the function returns "true", the program works fine.
But when the function returns "false",it gives the exception :
java.lang.NullPointerException

at org.drools.common.DefaultAgenda.getNextFocus(Unknown Source)

at org.drools.common.DefaultAgenda.fireNextItem(Unknown Source)

at org.drools.common.AbstractWorkingMemory.fireAllRules(Unknown Source)

at org.drools.common.AbstractWorkingMemory.fireAllRules(Unknown Source)

at com.wipro.loan.validation.bean.Final.main(Final.java:41)

I also tried with a additional rule of "MAIN" agenda-group but still it is giving the same problem.
My additional rule was :
rule "impossible"

agenda-group "MAIN"

when

eval(false)

then

System.out.println("The impossible rule has fired");

end 

I am sending my program in the attachment.
Now please give me the proper advice.
Have a great day.

With Regards
Prateek Katiyar

________________________________

From: rules-users-bounces@lists.jboss.org on behalf of rules-users-request@lists.jboss.org
Sent: Thu 10/4/2007 9:01 PM
To: rules-users@lists.jboss.org
Subject: rules-users Digest, Vol 11, Issue 35

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Today's Topics:

   1. Re: Migration 3 to 4 (replace "->") (Edson Tirelli)
   2. Re: BRMS - how to use variables on Action part? (Shahad Ahmed)
   3. Re: BRMS Guided Editor w/ variable binding (Shahad Ahmed)
   4. Re: Fucntion call in rule (Mark Proctor)

----------------------------------------------------------------------

Message: 1
Date: Thu, 4 Oct 2007 12:10:10 -0300
From: "Edson Tirelli" <tirelli@post.com>
Subject: Re: [rules-users] Migration 3 to 4 (replace "->")
To: "Rules Users List" <rules-users@lists.jboss.org>
Message-ID:
        <e6dd5ba30710040810l37cee366y4b91c074b386e4f8@mail.gmail.com>
Content-Type: text/plain; charset="iso-8859-1"

     Markus,

     We do support "->" in Drools 4.0 for backward compatibility, but we do
advise you to not use anymore, since we will drop support to it sometime in
the future. The alternative is simply to use an in-line eval:

BlaBlub( number : id, eval( BlaClass.staticFunction( number ) ) )

   Also, we now have auto-vivification of attributes, so you don't need to
bind "id" anymore, if you will only use it inside the eval:

BlaBlub( eval( BlaClass.staticFunction( id ) ) )

   I don't know if it was a typo in your e-mail, but you are missing a ")"
in the end of the line of your mapping:

[when]ist BlaBlub=BlaBlub(number : id -> ( BlaClass.staticFunction(number ))
)
    Hope it helps.

      Edson

2007/10/4, Markus Helbig <mhelbig81@googlemail.com>: