Ext 文件上传 fileuploadfield 帮帮忙 急呀,该如何解决

Ext.onReady(function(){

    Ext.QuickTips.init();

    var msg = function(title, msg){
        Ext.Msg.show({
            title: title,
            msg: msg,
            minWidth: 200,
            modal: true,
            icon: Ext.Msg.INFO,
            buttons: Ext.Msg.OK
        });
    };

    var fp = new Ext.FormPanel({
        renderTo: 'fi-form',
        fileUpload: true,
        width: 500,
        frame: true,
        title: 'File Upload Form',
        autoHeight: true,
        bodyStyle: 'padding: 10px 10px 0 10px;',
        labelWidth: 50,
        defaults: {
            anchor: '95%',
            msgTarget: 'side'
        },
        items: [{
            xtype: 'textfield',
            fieldLabel: 'Name',
            name:"common.name",
            id:"fileName"
        },{
            xtype: 'fileuploadfield',
            id: 'formFile',
            emptyText: 'Select an image',
            fieldLabel: 'Photo',
            name: 'common.fileStr',
            fileUpload : true,
            buttonText: '',
            buttonCfg: {
                iconCls: 'upload-icon'
            }
        }],
        buttons: [{
            text: 'Save',
            handler: function(){
                var v = Ext.getCmp('formFile').getValue();
                alert(v);
                if(fp.getForm().isValid()){
                    fp.getForm().submit({
                        url: "/common/common_fileLoad.action",
                        method:'POST',
                        waitMsg: 'Uploading your photo...',
                        success: function(fp, o){
                            msg('Success', 'Processed file "'+o.result.file+'" on the server');
                        }
                    });
                }
            }
        },{
            text: 'Reset',
            handler: function(){
                fp.getForm().getEl().dom.reset();
            }
        }]
    });

});