How can I make an HTML table with subcolumns?
<p>I would like to make an HTML table that expresses the following structure:</p>

<pre><code>ColumnHeading1            ColumnHeading2
SubHeading1A SubHeading1B SubHeading2A Subheading2B
data1A       data1B       data2A       data2B
data1A       data1B       data2A       data2B
data1A       data1B       data2A       data2B
data1A       data1B       data2A       data2B
...
</code></pre>

<p>How can I do this with tags like <code>&lt;table&gt;</code>,<code>&lt;tr&gt;</code>,<code>&lt;th&gt;</code>,<code>&lt;td&gt;</code>? I don't know how to align ColumnHeading2 with SubHeading2A.</p>