#!/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 l
+ocations & 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);
}
[download]

What I'm getting now is that the form doesnt remember the user's input data into all the form fields. The error arrows and messages show up correctly, just that each time I submit the form with errors, the input data will be erased which is surely unuser-friendly. I guess the general idea of doing it is: retrieve all the input data variables (ie $name, $username etc) and put them back into the form fields, all these in &printHTML subroutine.

But the exact way of doing that I'm not sure. I'd greatly appreciate any help here. Thanx in advance!

Edit by tye to add <p>,<readmore>.