title: How to define size of a button in Excel 2013 using customUI editor
body: <p>I am trying to create a new ribbon with 2 buttons in Excel 2013. I was able to create it using Custom UI editor thanks to 
  <a href="https://stackoverflow.com/questions/15509769/excel-customui-ribbon-layout">Excel CustomUI ribbon layout</a> and <a href="https://stackoverflow.com/questions/8850836/how-to-add-a-custom-ribbon-tab-using-vba/8852767#8852767">How to add a custom Ribbon tab using VBA?</a></p>
  
  <p>When I input the code as</p>
  
  <pre><code>&lt;button id="aa" label="CORE"  onAction = "HMA_CORE"/&gt; 
  </code></pre>
  
  <p>it works but once I try this code</p>
  
  <pre><code>&lt;button id="aa" label="CORE" size = "large" onAction = "HMA_CORE"/&gt;
  </code></pre>
  
  <p>and then click validate in the customUI it says that "size attribute is not declared". I am not sure what to add. I saw <a href="http://www.rondebruin.nl/win/s2/win009.htm" rel="nofollow noreferrer">http://www.rondebruin.nl/win/s2/win009.htm</a> as well, but the code looks the same. 
  Any help will be appreciated. 
  Thanks</p>
  
  <p>The code for the buttons looks like this</p>
  
  <pre><code>&lt;customUI xmlns="http://schemas.microsoft.com/office/2006/01/customui"&gt;
     &lt;ribbon&gt;
        &lt;tabs&gt;
           &lt;tab id="toolRibbon" label="HMA-FUNCTIONS"&gt;
              &lt;group id="groupDocument" label="HMA-xml outputs"&gt;
                 &lt;buttonGroup id="a"&gt;
                    &lt;button id="aa" label="CORE" onAction = "HMA_CORE"/&gt;
                    &lt;button id="ab" label="PLANT" onAction = "HMA_PLANT"/&gt;
                 &lt;/buttonGroup&gt;
              &lt;/group&gt;
           &lt;/tab&gt;
        &lt;/tabs&gt;
     &lt;/ribbon&gt;
  &lt;/customUI&gt;
  </code></pre>