Query by point

[Jeff Portwine]

I am trying to use layer->queryByPoint  in my php mapscript file, and I'm
getting an error
"Warning: [MapServer Error]: msSHPOpenFile(): No (NULL) filename provided".
I'm not exactly sure what this error means.... but i'm not very clear on how
to use queryByPoint.

I have a map with several points marked with a small red or blue circle gif.
I want to make it so that a user clicking on those points brings up a page
with information about that point.   As I understand it, using the
queryByPoint function looks at that point for a "shape" in a class that has
a template value set...  I'm assuming that the string stored in "template"
is supposed to be a URL or a file name  but i'm not entirely sure.

Can anybody offer any insight?

Thanks,
Jeff