title: How do you set only the image width of a Wordpress thumbnail
body: <p>I am trying to set the width of a post thumbnail using:</p>
  <pre class="lang-php prettyprint-override"><code>the_post_thumbnail()
  </code></pre>
  <p>The width of the image needs to be <code>210px</code> but the height is not meant to be fixed as all the images will be different sizes. I have tried:</p>
  <pre class="lang-php prettyprint-override"><code>the_post_thumbnail( array( 210, 0 ) ) 
  </code></pre>
  <p>But this does not work. Any ideas?</p>
  <p>Thanks.</p>