title: ExtJS 4 How to set the width of a ComboBox
body: <p>How can I set the width of a ComboBox input field?  I tried to set the width and it does not work.  I could not find any CSS variable for width though there is one for height <code>($form-field-height)</code>.</p>
  
  <p>I have also tried to set width in fieldStyle.</p>
  
  <pre><code>    fieldStyle: {
          width: '100px'
      }
  </code></pre>
  
  <p>I am able to change the height though.  The following works.</p>
  
  <pre><code>    fieldStyle: {
          height: '60px'
      }
  </code></pre>