def upload_image(data,mimetype,filename,title=nil,description=nil,
tags=nil, is_public=nil,is_friend=nil,is_family=nil)
form = Flickr::MultiPartForm.new
sig = make_signature(title,description, tags, is_public,
is_friend, is_family)
form.parts += prepare_parts(data,mimetype,filename,title,
description, tags, is_public, is_friend,
is_family, sig)
res = REXML::Document.new(send_form(form).body)
error(res.elements['/rsp/err']) if res.elements['/rsp/err']
val = res.elements['/rsp/photoid'].text
return val
end