```ruby
module CopyMoveHelper   
  def page_parent_select_tag
    home = Page.find_by_parent_id nil
    list = build_tree home, []
    options = options_for_select list, (@page.parent ? @page.parent.id : nil)
    select_tag 'parent', options    
  end
  
  def build_tree page, list, level = 0
  	label = "#{'-'*level}#{page.title}"
  	id = page.id
  	list << [label, id]
  	page.children.each do |p|
  		build_tree p, list, level + 1
  	end
  	list
  end
end```

Allow copy/move to copy between sites when multi_site is installed.
user
```ruby
module CopyMoveHelper   
  def page_parent_select_tag
    homes = Page.find_all_by_parent_id nil
    list = homes.inject([]) do |l, home|
      l.concat build_tree(home, [])
    end
    options = options_for_select list, (@page.parent ? @page.parent.id : nil)
    select_tag 'parent', options    
  end
  
  def build_tree page, list, level = 0
  	label = "#{'-'*level}#{page.title}"
  	id = page.id
  	list << [label, id]
  	page.children.each do |p|
  		build_tree p, list, level + 1
  	end
  	list
  end
end```
assistant