Query shapes in certain extent

[G-Net Consulting]

Hello list:

What is the best way to access the shapes and locations of
points marked within a given map?  I have several hundred
points I need to find that are displayed from a given layer.
What's the best way to accomplish this?

I currently have a layer that has over 5,000 points marked
through the US.  As they drill down, I plan to use JavaScript
to display information about each one.  In the dbf file, I have
an ID that corresponds to an ID in a MySQL table.  I just
to get the ID"s of just the one displayed inside the chosen
extent.

I'm using PHP 4.3.3 with MapScript 4.2.1 on Redhat 9.

Thanks in advance.

Joel