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)