Rails + jQuery Ajax

$(document).ajaxSend(function(event, request, settings) {
	// pass authenticity token with requests
	// requires global AUTH_TOKEN var to be set by Rails:
	// <%= javascript_tag "var AUTH_TOKEN = #{form_authenticity_token.inspect};" if protect_against_forgery? %>
	settings.data = (settings.data ? settings.data + "&" : "") + "authenticity_token=" + encodeURIComponent( AUTH_TOKEN );
	// make respond_to jump to the js block
	if ( settings.dataType == 'html' ) request.setRequestHeader("Accept", "text/javascript");
});