ims = xhr.getResponseHeader('X-Remoteglot-Last-Modified');
var num_viewers = xhr.getResponseHeader('X-Remoteglot-Num-Viewers');
update_board(board, data, num_viewers);
ims = xhr.getResponseHeader('X-Remoteglot-Last-Modified');
var num_viewers = xhr.getResponseHeader('X-Remoteglot-Num-Viewers');
update_board(board, data, num_viewers);