 <p>Why make it so complex? Just declare the width and leave it at that:</p> <pre><code>#resulttbl{ width:100%; } </code></pre> <p>If for some reason that doesn't work, try using <code>!important</code>. If that does work then another rule is taking a higher precedence then the current rule.</p> <pre><code>#resulttbl{ width:100% !important; } </code></pre> <p><strong>update</strong></p> <p>cHao is correct. My answer is really just good advice at this point.</p>