Extjs4.2 grid Store 删除问题

解决grid该页删除后向前跳页的问题
if((Ext.getCmp("nutchConfigurationGrid").getStore().totalCount-1)%Ext.getCmp('nutchConfigurationGrid').getStore().pageSize==0){
var pageIndex = (Ext.getCmp("nutchConfigurationGrid").getStore().totalCount-idArray.length)/Ext.getCmp('nutchConfigurationGrid').getStore().pageSize;

if(pageIndex != 0){ //indicate that there has data after delete
Ext.getCmp('nutchConfigurationGrid').getStore().currentPage = 1;
}else{
Ext.getCmp('nutchConfigurationGrid').getStore().currentPage = pageIndex;
}
}
Ext.getCmp("nutchConfigurationGrid").getStore().load();