function vote(a_url,callback)
{
		if(is_authenticated)
		{
			$.ajax({
		    url: a_url,
		    type: 'POST',
		    data: "",
		    timeout: 10000,
		    error: function(){
		        alert('Error');
		    },
		    success: callback
			});
		}
		else
		{
			login_dialog.load();
			login_dialog.callback = function(button)
			{
				if(button==1)
					//点确定
					vote(a_url,callback);
			}
			
		}
	
}