print 'Select a number: ';
my $input = <STDIN>;
chomp $input;
if (exists $users{$input}) {
   print "Number entered is : $users{$input} \n";
   print "User for the number $users{$input} is :  \n";
   print "Comments for the number $users{input} is : \n";
} else {
    print "Unknown number.\n";
}

##</code><code>##

  Number entered is : 12345678
  User for number 123456789 is : Sam  
  Comments for the number 123456789 is : Changed "abc" in the file