How is your database configured?
do any of the columns in the Orders or order Details table contain reserved words? A list of reserved words can be found here:
286335
and here:
321266
The error you re reporting is a very generic error. Are you testing using IE? There is a settings in IE to "Show Friendly HTTP error messages. Turn this off and you may get a more descriptive error that will help in trouble shooting the problem. Or you could try testing in FireFox.