Issue: Grid panel populates data is so slow

Hi,

I get the JSON response and try to populate data to my grid.

The function takes around 3 sec to finish ( 20 records ) and record is in the browser memory already. I am wondering why it takes so slow.

Code:

for(var i=0;i<record.get("attach").length;i++)

{

var filename = record.get("attach")[i].filename ;

var sender = record.get("attach")[i].From;

var dateformat = new Date();

var edit = '';

var currentdate = record.get("attach")[i].Date;

var myRecord = Ext.create('Myapp.model.DocumentModel', {

File: filename,

From: sender,

Date: currentdate,

Action: edit,

attachId: record.get("attach")[i].attachid,

docId: record.get("attach")[i].docId,

docName:record.get("attach")[i].docName

});

Ext.getCmp('DocUploadGrid').getStore().add( myRecord );

}

Welcome to any suggestion.

Thanks in advance.