Hi Robert,
The thing I would do is just a bit of hand coding if you are comfortable doing it.
How I would do it would be to first create hidden fields that contain the width and height of the original image in your form.
Then inside your update code after the trigger for when the form is posted, make a few modifications.
Create arbitrary variables and write a simple "if" statement to see if there was a new image in the upload field like this:
if ($_POST['imagefile'] != "" OR $_POST['imagefile] != "NULL") {
$imagewidth = DFPimagewidth;
$imageheight = DFPimageheight;
} else {
$imagewidth = hiddenfieldwidth;
$imageheight = hiddenfieldheight;
}
Then in the actual update statement, change the value received by the image width column to "$imagewidth" and the image height column to "$imageheight".
Hope that helps,
Brian