sub add_if_defined {
  my ($columnname,$queryvar) = @_;

  die "add_if_defined: First parameter (columnname) may not be empty (maybe you supplied columnname and queryvar in the wrong order ?)" 
    unless $columnname;

  if (defined($queryvar) && $queryvar ne '') {
   push @where_clause,"UPPER($columname) LIKE UPPER('%$queryvar%')";
   push @entries, $columnname;
  }
};