What is ABS_PATH
Pay attention to ABS_PATH variable. Make sure it is the absolute URL to phpGrid folder in the web browser. This value tells your script where to find phpGrid library on the web server.
For instance, if the URL to get to the phpGrid is http://www.yoursite.com/phpGrid, or http://localhost/phpGrid, the ABS_PATH should be “/phpGrid”;
or if the URL to phpGrid is http://www.yoursite.com/admin/phpGrid, or http://localhost/admin/phpGrid, the ABS_PATH should be “/admin/phpGrid”,
and so forth.