The ajax request for filtering

gistfile1.js

function handle_filter_request(req,res,next) {
  filter = req.param("filter") ? JSON.parse(req.param("filter")) : {}
  if(filter[dimension]){
  	dimension.filter(filter[dimension]);
  }
  results[dimension]= {values:group.all(),top: group.top(1)[0].value};
  res.writeHead(200, { 'content-type': 'application/json' });
  res.end((JSON.stringify(results)));
}