[ExtJs4.0]根据一个文本框输入的内容自动填写到另外一个文本框内

一个增加数，一个减少数，随便输入其中一个另外一个都会自动输入

{

            xtype: 'textfield',

            id: 'IncreaseId',

            fieldLabel: '增?加¨®数ºy<span style="color: red;" >*</span>',

            regex: /^[0-9]*$/,

            regexText: '请?输º?入¨?整?数ºy',

            width: 400,

            name: 'IncreaseNumber',

            allowBlank: false,

            maxLength: 10,

            maxLengthText: '输º?入¨?过y长¡è',

            onBlur: function () {

                var thisForm = this.up('form');

                var increaseNumberValue = thisForm.getForm().findField('IncreaseId').getValue();

                thisForm.getForm().findField('ReduceId').setValue(increaseNumberValue);

            }

        }

, {

            xtype: 'textfield',

            fieldLabel: '减?少¦¨´数ºy<span style="color: red;" >*</span>',

            id: 'ReduceId',

            regex: /^[0-9]*$/,

            regexText: '请?输º?入¨?整?数ºy',

            width: 400,

            name: 'ReduceNumber',

            allowBlank: false,

            maxLength: 10,

            maxLengthText: '输º?入¨?过y长¡è',

            onBlur: function () {

                var thisForm = this.up('form');

                var reduceNumberValue = thisForm.getForm().findField('ReduceId').getValue();

                thisForm.getForm().findField('IncreaseId').setValue(reduceNumberValue);

            }

        },