span class="op">&lt;</span> <span class="op">(</span><span class="va">node_width</span> <span class="op">/</span> <span class="fl">2</span><span class="op">)</span><span class="op">)</span> <span class="op">{</span>
        <span class="co"># Display node information if cursor is over a stratum box.</span>

        <span class="co"># Determine stratum name from x and y coord, and the n.</span>
        <span class="va">node_row</span> <span class="op">&lt;-</span> <span class="va">pbuilt</span><span class="o