exception handling

Hi     I have code in model as

def self.record_paginate_pb(search_pb_ui_hash,page) problem_number=search_pb_ui_hash[:number] problem_priority_id=search_pb_ui_hash[:problem_priority_id] search_problem = self.find_where_options :order => 'created_on DESC' do


    pb.number1.downcase =~ "%"+problem_number.downcase+"%" if !problem_number.nil?     pb.problem_priority_id== problem_priority_id   end           rescue ActiveRecord::ActiveRecordError => e:             puts 'error happened '+e.to_s             else           paginate search_problem.update( :per_page=>10,:page => page ) end   and this is called from controller as @search_pb_result=Problem.record_paginate_pb(params[:problem], params[:page])

I am new to ruby's exception handling (learning)..How can I write a rescue block for the above code ..I tried like above but is not working..Could you please help me and also point to some good tutorials on rails exception handling?

Thanks in advance Sijo