#!/usr/bin/perl

if ($ENV{'REQUEST_METHOD'} eq 'POST') {

# Get the input

 read(STDIN, $buffer, $ENV{'CONTENT_LENGTH'});

# Split the name-value pairs

 @pairs = split(/&/, $buffer);

# Load the FORM variables

 foreach $pair (@pairs) {
 ($name, $value) = split(/=/, $pair);
 $value =~ tr/+/ /;
 $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;

 $FORM{$name} = $value;

}

&thank_you;

}

sub thank_you {

 print "Content-type: text/html\n\n";
 print "<HTML>\n";
 print "<HEAD>\n";
 print "<TITLE>Math and You!</TITLE>\n";
 print "</HEAD>\n";
 print "<BODY BGCOLOR=#FFFFCC TEXT=#000000>\n";
 print "<H3>Here are those answers you requested...</H3>\n";
 print "\n";
 print "\n";

# Simply list the choices the user made
 print "You Chose $FORM{singledgt}, $FORM{doubledgt}, and $FORM{dinner}. Fine choices.";

# Add the two numbers together
 print "Did you know that $FORM{singledgt} plus $FORM{doubledgt} equals ";
 print $FORM{singledgt} + $FORM{doubledgt};

# Square the single digit
 print "$FORM{singledgt} squared is ";
 print $FORM{singledgt}*$FORM{singledgt};

# How much bigger is the bigger digit than the smaller digit?
 print "The number $FORM{doubledgt} is ";
 print $FORM{doubledgt} - $FORM{singledgt};
 print " greater than $FORM{singledgt}";

# Figure Tip
 print "If you spent $$FORM{dinner} for dinner, the traditional 15% tip would be: $";
 print $FORM{dinner}*.15;
 print " for total of $";
 print $FORM{dinner}+($FORM{dinner}*.15);
 print ".";

# Use Branch to test if user spends over 100 dollars on dinner
 if ($FORM{dinner} < 100)
 {print "Wait! You didn't spend at least 100 dollars on a dinner date? Cheap!";}
 else
 {print "Wait! You really spend that much on dinner dates? Can we go out? I'm hungry.";}

 print "\n";
 print "</BODY>\n";
 print "</HTML>\n";
 exit(0);
}