A form is created in the Buy column using a powerLens property. This form consists of the
following: <form action="ex901.php" method=POST>
<input type=text name=q size=2>
<input type=submit value=Buy>
<input type=hidden name=p value="$ProductID">
The rows are grouped by CategoryID using the groupLens property.
The Buy column is colored using the colorLens property.