#!/usr/bin/perl
    
    use strict 'refs';
    use Plack::Request;
    use Data::Dumper;
    
    my $app = sub {
    
    	my $env = shift;
    	my $form = Plack::Request->new($env);
    	
    	print Dumper ( $form->body_parameters ) ;
    	
    	#how to convert $form->body_parameters to new  %form_hash?
    	
    	my %form_hash;
    	my %cb_hash;
    	
    	foreach my $key (sort(keys(  %form_hash   ))) {
    
    	 if ( substr($key,0,2) eq "c_" ){    
    				
    		my $cb_key = $key;
            	my $cb_val = $form_hash{$key};
            	$cb_hash{$cb_key} = $cb_val; 
    
    			}
    
    	}
    
    };