grid中的两个store 相等

var store=new Ext.data.Store({
url:"student.ejf?cmd=list",
reader:new Ext.data.JsonReader({
root:"result"},
["id","name","organization","homepage"])
});

等同于


var store=new Ext.data.JsonStore({
url:"student.ejf?cmd=list",
root:"result",
fields:["id","name","organization","homepage"]});