title: how to enable button in extjs?
body: <p>I am new to ExtJs(using EXT js 4 ), I am trying out simple code.</p>
  
  <p>I have a submit button which is set disabled by default</p>
  
  <pre><code>buttons: [{
      text: 'Submit',
      id:'submit',
      disabled:true  
  }]
  </code></pre>
  
  <p>I want to enable the button based on certain conditon.Something like </p>
  
  <pre><code>if (validation_status== "success") {
      //Enable the submit button
      //Ext.get('submit').dom.disabled = false; -- Not working
      //Ext.get('submit').enable(); -- Not working            
  }
  </code></pre>
  
  <p>I tried above 2 option. Which did not worked for me.
  Can anyone help me out?</p>