title: extjs input text maskRe
body: <p>In Ext JS, the following <code>maskRe</code> doesn't work in that it doesn't put the restriction of max 5 characters on the text field, why?</p>
  
  <pre><code>{
    xtype: 'textfield',
    fieldLabel: '* Zip Code',
    allowBlank: false,
    maskRe: /\d{0,5}/i
  }
  </code></pre>