How to display block using hook_block on specific pages only

Question

I am creating the block using the following code , but i need to dsiplay this block only in specific pages only . How can i achieve this ?

function mailusers_block($op = 'list', $delta = 0, $edit = array()) {
  if ($op == 'list') {
    $blocks[0] = array(
      'info' => t('User Management block'), 
      'weight' => 0, 
      'status' => 1, 
      'region' => 'left',
    );

    return $blocks;
  }

  else if ($op == 'save' && $delta == 0) {
    variable_set('test_block_items', $edit['items']);
  }
  else if ($op == 'view') {
    switch ($delta) {
      case 0:
        // Your module will need to define this function to render the block.
        $block = array(
          'subject' => t('User Group Management'), 
          'content' => mailuser_block_conent(),
        );
        break;
    }
    return $block;
  }
}

function mailuser_block_conent(){
    //create menu links      
     $ret = '<a href="'.$base_url.'/mailusers/adduser">Add User </a>';
     return $ret;
}

Answer 1

You need to add 'visibility' option that is equal to 1 and 'pages' option that should be a string that contains one or more page paths separated by '\n', '\r', or '\r\n' for your block information

 $blocks[0] = array(
  'info' => t('User Management block'), 
  'weight' => 0, 
  'status' => 1, 
  'region' => 'left',
  'visibility' => 1,
  'pages' => 'node/1'
);