implemented javascripts for approval/disapproval/unapproval from post/show page

app/models/unapproval.rb

@@ -4,7 +4,22 @@ class Unapproval < ActiveRecord::Base
   belongs_to :unapprover, :class_name => "User"
   belongs_to :post
   validates_presence_of :reason, :unapprover_id, :unapprover_ip_addr
+  validate :validate_post_is_active
   before_validation :initialize_unapprover, :on => :create
+  before_save :flag_post
+  
+  def validate_post_is_active
+    if post.is_pending? || post.is_flagged? || post.is_removed?
+      errors[:post] << "is inactive"
+      false
+    else
+      true
+    end
+  end
+  
+  def flag_post
+    post.update_attribute(:is_flagged, true)
+  end
   
   def initialize_unapprover
     self.unapprover_id = CurrentUser.id