NAME
    Debug::EchoMessage - Display debug messages based on levels

SYNOPSIS
        my $self = bless {}, "main";
        use Debug::EchoMessage;
        $self->debug(2);   # set debug level to 2
        # The level 3 message will not be displayed
        $self->echoMSG("This is level 1 message.", 1);
        $self->echoMSG("This is level 2 message.", 2);
        $self->echoMSG("This is level 3 message.", 3);  

DESCRIPTION
    The package contains the modules can be used for debuging or displaying
    contents of your runtime state. You would first define the level of each
    message in your program, then define a debug level that you would like
    to see in your runtime.

    { # Encapsulated class data _debug =>0, # debug level }

  debug($n)

    Input variables:

      $n   - a number between 0 and 100. It specifies the
             level of messages that you would like to
             display. The higher the number, the more
             detailed messages that you will get.

    Variables used or routines called: None.

    How to use:

      $self->debug(2);     # set the message level to 2
      print $self->debug;  # print current message level

    Return: the debug level or set the debug level.

  echoMSG($msg, $lvl)

    Input variables:

      $msg - the message to be displayed. No newline
             is needed in the end of the message. It
             will add the newline code at the end of
             the message.
      $lvl - the message level is assigned to the message.
             If it is higher than the debug level, then
             the message will not be displayed.

    Variables used or routines called:

      debug - get debug level.

    How to use:

      # default msg level to 0
      $self->echoMSG('This is a test");
      # set the msg level to 2
      $self->echoMSG('This is a test", 2);

    Return: None.

    This method will display message or a hash array based on *debug* level.
    If *debug* is set to '0', no message or array will be displayed. If
    *debug* is set to '2', it will only display the message level ($lvl) is
    less than or equal to '2'. If you call this method without providing a
    message level, the message level ($lvl) is default to '0'. Of course, if
    no message is provided to the method, it will be quietly returned.

    This is how you can call *echoMSG*:

      my $df = DataFax->new;
         $df->echoMSG("This is a test");   # default the msg to level 0
         $df->echoMSG("This is a test",1); # assign the msg as level 1 msg
         $df->echoMSG("Test again",2);     # assign the msg as level 2 msg
         $df->echoMSG($hrf,1);             # assign $hrf as level 1 msg
         $df->echoMSG($hrf,2);             # assign $hrf as level 2 msg

    If *debug* is set to '1', all the messages with default message level,
    i.e., 0, and '1' will be displayed. The higher level messages will not
    be displayed.

  disp_param($arf,$lzp)

    Input variables:

      $arf - array reference
      $lzp - number of blank space indented in left

    Variables used or routines called:

      echoMSG - print debug messages
      debug   - set debug level
      disp_param - recusively called

    How to use:

      use Fax::DataFax::Subs qw(:echo_msg);
      my $self= bless {}, "main";
      $self->disp_param($arf);

    Return: Display the content of the array.

CODING HISTORY
    * Version 0.01
        04/15/2000 (htu) - Initial coding

    * Version 0.02
        04/16/2001 (htu) - finished debug and echoMSG

    * Version 0.03
        05/19/2001 (htu) - added disp_param

    * Version 1.00
        06/25/2002 (htu) - added HTML format in disp_param

    * Version 1.01
        06/25/2002 (htu) - fixed the NAME title

FUTURE IMPLEMENTATION
    * no plan yet
AUTHOR
    Copyright (c) 2004 Hanming Tu. All rights reserved.

    This package is free software and is provided "as is" without express or
    implied warranty. It may be used, redistributed and/or modified under
    the terms of the Perl Artistic License (see
    http://www.perl.com/perl/misc/Artistic.html)