In extjs how to get downloaded file contents

I am working on the ability to upload files in extjs + php. I want to download a file or image from extjs and send it to the server side, which I am developing in PHP. In extjs, I have the view file code as -

Ext.define('Balaee.view.kp.dnycontent.Content', 
{
    extend:'Ext.panel.Panel',
    requires:[
              'Balaee.view.kp.dnycontent.ContentView'
              ],
    id:'ContentId',
    alias:'widget.Content',
    title:'This day in a history',
    items:[
     {
        xtype: 'fileuploadfield',
        hideLabel: true,
        emptyText: 'Select a file to upload...',
        id: 'upfile',
        //name:'file',
         width: 220
}],
    buttons:[
    {
        text: 'Upload',
        handler: function () {
            var file = Ext.getCmp('upfile').getEl().down('input[type=file]').dom.files[0];            console.log(file);
             var reader = new FileReader();
             filecontent=reader.readAsBinaryString(file);
             console.log(filecontent);
        }
    }
]

});

Therefore, when I try to load an animation file with the above code. The above line: Ext.getCmp('upfile').getEl().down('input[type=file]').dom.files[0];stores file information as:

File {
    webkitRelativePath: "", 
    lastModifiedDate: Tue Jul 14 2009 11:02:31 GMT+0530 (India Standard Time), 
    name: "Koala.jpg", 
    type: "image/jpeg", 
    size: 780831…
 }

i.e. The information associated with the file is obtained. But the actual contents of the file does not get. So what do I need to change to get the downloaded file?