osCommerce broke

Hey all,

Visited one of the sites I did for someone this morning - and found it to be completely broken.
[URL=“http://weldco.ca”]
http://weldco.ca - click on online store

i havent made any changes that i can remember in the past while

instead of opening the selected page, it asks if i want to open/download the php file.

i cant even access the administration panel.

anyone know why?