function getRss(php_url, rss_url, subject, _id){
	var data = '&rss_url='+rss_url+'&subject='+encodeURIComponent(subject);
	
	// リクエスト送信（＆innerHTML書き込み）
	new  Ajax.Request(php_url,{
		 method: 'POST'
		,parameters: data
		,onSuccess:function(httpObj){
			var html_str = httpObj.responseText;
			var obj = document.getElementById(_id);
			if(obj != undefined){
				obj.innerHTML = decodeURIComponent(html_str);
			}
		}
	});
}