$sql_string = make_anded_statement ( username => $form_username,
                                     password => $form_password,
                                     name     => $form_name );

sub make_anded_statement {
  my ( %args ) = @_;
  my @keys = keys %args;
  my $where_string = '';
  my $ANDING = 0;
  foreach my $i ( 0 .. $#keys ) {
    if ( $args{$keys[$i]} ) {
      $where_string .= $keys[$i] . '=' . $args{$keys[$i]} . ' ';
      $ANDING = 1;
    }
    if ( $ANDING && $args{$keys[$i+1]} ) {
      $where_string .= 'AND ';
    }
  }
  return "SELECT FROM table WHERE $where_string";
}