from pure javascript to prototypejs

Is there a way to write the following pure javascript in prototypejs

var xhr = new XMLHttpRequest();

xhr.open("POST", "/photos开发者_JAVA技巧?authenticity_token=" + token 
                        + "&photo[name]=" + img.name
                        + "&photo[size]=" + img.size);

xhr.overrideMimeType('text/plain; charset=x-user-defined-binary');
xhr.sendAsBinary(bin);

I did this but I don't know how to upload the bin file

var url = '/photos';
new Ajax.Request(url, {
  method: 'post',
  parameters: { 
    authenticity_token: token,
    'photo[name]': img.name,
    'photo[size]': img.size       
  },
  onSuccess: function(transport) {
    alert('Yeah');
  }
});

thanks

sendAsBinary method is FireFox specific so it is not implemented in the prototypejs library as this library is intended to work cross browser.

Darin Dimitrov is spot on.

However if it's ajax file uploading you're ultimately after i'd suggest yahoo's uploader. Simple example: http://developer.yahoo.com/yui/examples/uploader/uploader-simple-button.html

FYI swfupload is also a solid file uploader that doesnt require any library