title: change border color of text field in ExtJS
body: <p>I am trying to validate a textfiled value on ajax request call.
  and I want to turn the color of the border of text field as green if the value is valid.</p>
  
  <p>I tried doing so by calling <code>Ext.getCmp('loginid').style = 'valid-text';</code>
  and also I tried <code>Ext.getCmp('loginid').filedClass = 'valid-text';</code></p>
  
  <p>where valid-text has the code:</p>
  
  <pre><code>&lt;style&gt;
      .valid-text{ 
           background-color:#bbb; 
           border-color:#008B00; 
       } 
  &lt;/style&gt;
  </code></pre>
  
  <p>I dont understand why it is not taking this class.</p>
  
  <p>Could anyone please help.</p>
  
  <p>Thanks in advance!</p>