function showCommentForm(update_id, list_id, doc_id, url){
	var formName = 'comment_add_form';
	var mydate = new Date();
	var mytime = mydate.getTime();
	var requestBaseUrl = '/tech/ajax_doc_comments/form/json/' +doc_id+ '?a=1';
	var requestUrl = requestBaseUrl;
	var method = 'get';
	var query_param = '';
	if(url) {
		requestUrl = url;
		method = 'post';
		if($('comment_add_form')){
			query_param = Form.serialize(formName);
		}
	}
	new Ajax.Request(requestUrl + '&t=' + mytime, {
		method: method,
		parameters: query_param,
		requestHeaders: {'If-Modified-Since': 'Thu, 01 Jun 1970 00:00:00 GMT'},
		
		// 結果コンテンツの反映
		onSuccess: function(request){
			// 正常処理
			var execute_flg = request.responseJSON.execute;
			if(execute_flg == 1){
				showCommentList(list_id, doc_id); // 一覧の更新
			}
			$(update_id).innerHTML = request.responseJSON.contents;
		},
		onComplete: function(request){
			// フォームをAJAX対応
			$(formName).observe('submit', function(event) {
					$('SubmitSave').hide();
					event.stop();
					showCommentForm(update_id, list_id, doc_id, requestBaseUrl);
			});
			if($('err_msg')){
				$('err_msg').highlight();
			}
			if($('info_msg')){
				$('info_msg').highlight();
			}
		}
	});
}