gistfile1.js

Request.Weather = new Class({
                Extends: Request.JSONP,

                options: {
                    url: 'http://query.yahooapis.com/v1/public/yql?q=use%20%22http%3A%2F%2Fthinkphp.ro%2Fapps%2FYQL%2Fweather-forecast%2Fweather.woeid.xml%22%20as%20weather%3B%20select%20*%20from%20weather%20where%20location%3D%22{term}%22%20and%20unit%3D%22c%22%3B',
                    data: {
                        format: 'json'
                    }
                },

                initialize: function(term,options) {
                   this.parent(options);  
                   this.options.url = this.options.url.substitute({term: term}); 
                }
   });

   window.addEvent('domready',function(){ 

   new Request.Weather('london',{
           onSuccess: function(o){
                var title = '<p style="color: blue"><strong>'+o.query.results.weather.rss.channel.item.title+'</strong></p>',
                    description = o.query.results.weather.rss.channel.item.description;               
                $('weather').set('html',title+description);
           }   
   }).send();

   });