[求教]Ajax请求Action出现在异常.

new Ajax.Request('/hello',
         {
            method : 'post',
            parameters :
            {
               text : old_text
            }
            ,
            asynchronous : true,
            onSuccess : function(transport)
            {
                alert(transport.responseText);
               this.setValue(transport.responseText);
               $('php?name=editor" onclick="tagshow(event)" class="t_tag">editor_switch_spinner').hide();
            }
            .bind(this)
         }
         );