anchor.diff:  -export([main/0, event/1, api_event/3, comet_loop/1]).
   
   %% Common page CCS styles
  --define(MESSAGE_STYLE, <<"position: fixed; width: 100%; top: 120px; z-index: 1; display: none;">>).
  +-define(MESSAGE_STYLE, <<"position: fixed; width: 100%; top: 55px; z-index: 1; display: none;">>).
   -define(CONTENT_COLUMN_STYLE, <<"padding-right: 0">>).
   -define(NAVIGATION_COLUMN_STYLE, <<"border-left-width: 0; width: 20px; padding-left: 0;">>).
   -define(DESCRIPTION_STYLE, <<"border-width: 0; text-align: right; width: 10%; padding-left: 0; padding-right: 0;">>).
  
positive.code:             class = <<"dialog dialog-danger">>
          },
          #panel{
              style = <<"position: relative; margin-top: 200px; margin-bottom: 50px;">>,
              body = #table{
                  class = <<"table table-bordered table-striped">>,
                  style = <<"width: 50%; margin: 0 auto; table-layout: fixed;">>,
                  body = #tbody{
                      id = <<"spaces">>,
                      body = #tr{
                          cells = [
                              #th{
                                  style = <<"font-size: large;">>,
                                  body = <<"Spaces">>
                              },
                              #th{
                                  style = ?NAVIGATION_COLUMN_STYLE,
                                  body = spinner()
                              }
                          ]
                      }
                  }
              }
          }
      ].
  
  
  %% spaces_submenu/0
  %% ====================================================================
  %% @doc Submenu that will end up concatenated to top menu.
  -spec spaces_submenu() -> [#panel{}].
  %% ====================================================================
  spaces_submenu() ->
      [
          #panel{
              class = <<"navbar-inner">>,
              style = <<"border-bottom: 1px solid gray; padding-bottom: 5px;">>,
              body = [
                  #panel{
                      class = <<"container">>,
                      body = [
                          #panel{
                              class = <<"btn-group">>,
                              style = <<"margin: 12px 15px;">>,
                              body = #button{
                                  id = <<"create_space_button">>,
                                  postback = create_space,
                                  class = <<"btn btn-inverse">>,
                                  style = <<"height: 34px; padding: 6px 13px 8px;">>,
                                  body = <<"Create Space">>
                              }
                          },
                          #panel{
                              class = <<"btn-group">>,
                              style = <<"margin: 12px 15px;">>,
                              body = #button{
                                  id = <<"join_space_button">>,
                                  postback = join_space,
                                  class = <<"btn btn-inverse">>,
                                  style = <<"height: 34px; padding: 6px 13px 8px;">>,
                                  body = <<"Join Space">>
                              }
                          }
                      ]
                  }
              ]
          }
  
negative.code:                 image = <<"/images/spinner.gif">>
              }
          },
          vcn_gui_utils:top_menu(spaces_tab),
          #panel{
              id = <<"ok_message">>,
              style = ?MESSAGE_STYLE,
  