[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);
}
},