ext gridpanel添加列和响应函数

ext gridpanel添加列和响应函数：

{     
			     header : 'extraColumn',  
			     dataIndex : ' ',  
			     width : 100,  
			     renderer: function (value, meta, record) {  
					var formatStr += "<a href='javascript:void({0});' onclick='javscript:return false;'>增加</a>";  
					var resultStr = String.format(formatStr, record.get('id'));  
					     return "<div class='controlBtn'>" + resultStr + "</div>"; 
			      }
		     },