Issue with METHOD in prototype / Ajax.Request

I am trying to call yahoo api via Ajax to find current weather:

var query = "select * from weather.forecast where l开发者_开发问答ocation in ('UKXX0085','UKXX0061','CAXX0518','CHXX0049') and u='c'";
var url = 'http://query.yahooapis.com/v1/public/yql?q=' + encodeURIComponent(query) +'&rnd=1344223&format=json&callback=jsonp1285353223470';

new Ajax.Request(url, {
   method: 'get',
   onComplete: function(transport) {
      alert(transport.Status); // say 'null'
      alert(transport.responseText); // say ''
   }
});

I noticed, that instead of GET firebug says OPTIONS. What is it and how I can use force prototype to use GET?

Here is functionality which i am trying to recreate.

And here is full URL which I am trying to access:

<a href="http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20weather.forecast%20where%20location%20in%20(%27UKXX0085%27%2C%27UKXX0061%27%2C%27CAXX0518%27%2C%27CHXX0049%27)%20and%20u%3D%27c%27&rnd=1344223&format=json&callback=jsonp1285353223470">http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20weather.forecast%20where%20location%20in%20(%27UKXX0085%27%2C%27UKXX0061%27%2C%27CAXX0518%27%2C%27CHXX0049%27)%20and%20u%3D%27c%27&rnd=1344223&format=json&callback=jsonp1285353223470</a>

After hours of trying to debug the same issue myself, I came to the following conclusion.

I believe this happens because of XSS counter-measures in newer browsers.

You can find very detailed information about these new counter-measures here:

https://developer.mozilla.org/en/http_access_control

Basically, a site can specify how "careful" the browser should be about allowing scripts from other domains. If your site, or a site from which you're loading external JavaScript code, includes one of these pieces of "browser advice", newer browsers will react by enforcing a stronger XSS policy.

For some reason, Prototype's Ajax.Request, under Firefox, seems to react by attempting to do an OPTIONS request, rather than a GET or POST, so perhaps Prototype has not been updated to correctly handle these new security conditions.

At least that was the conclusion in my case. Maybe this clue can help with your case...