#!/usr/bin/perl 

   use CGI::Carp "fatalsToBrowser";
   use DBI;
   
### Subroutine that parses the form.
sub parse_form {
	
  # Get the input.
  read(STDIN, $buffer, $ENV{'CONTENT_LENGTH'});
  # Splits the name-value pairs
  @pairs = split(/&/, $buffer);
  foreach $pair (@pairs) {
    ($name, $value) = split(/=/, $pair);
  $FORM{$name} = $value;
}

### Subroutine that catches form variables
sub get_variables {

   $name	= $FORM{'name'};	
   $username    = $FORM{'username'};
   $email	= $FORM{'email'};
   #other variables follow
   .
   .
   .
}
### Subroutine that validates form submission
sub validate_form {
   #validation routines, eg:
   if ($name eq "") {
   	$error = '1';
   	$errname = '1';
        $error1 = "<a href=\"javascript:alert('Please enter a name.')\"><img src=\"/pics/generic/error.gif\" border=\"0\"></a>";
   }
   .
   .
   .
}

### Subroutine that generates the page with error indications
sub printHTML {   

  print "Content-Type: text/html\n\n";	
  $filename    = "signup.htm";
  open (INFILE,$filename);
  while (<INFILE>) {

  #alot of substitutions here...eg:
  if ($errname='1') { s/<input type="hidden" name="hiddenField" value="~error1~">/$error1/g; }
  .
  .
  .
    
  print $_;
  }
  close(INFILE);
}

########### Main body

#form submitted with arguments, so process it
if ($ENV{'CONTENT_LENGTH'}) {

   &parse_form;
   &get_variables;
   &validate_form;
   
   #if no error, insert into db
   if ($error eq '0') {
   
	#insert form data into db

   }
   #if errors, substitute hidden fields with arrows indicating error locations & messages
   else {
	&printHTML;
   }

}

#first time in: no arguments in form, so present empty form
else  	{
        print "Content-Type: text/html\n\n";	
  	$filename    = "signup.htm";
    	open (INFILE,$filename);
      	while (<INFILE>) {
      		print $_;
	}
	close (INFILE);
}