function hook_block($op = 'list',$delta = 0,$edit = array()) {
  switch ($op) {

    case 'list':
      $blocks[0]['info'] = t('Block 1');
      $blocks[1]['info'] = t('Block 2');
      return $blocks;

    case 'configure':
      if ($delta == 0) {
        // Block 1
      }
      else if ($delta == 1) {
        // Block 1
      }

 ....

}