web service error when passing wstoken and wsfunction in http

Hi,

I have only a gentleman's knowledge of Moodle and am trying to try out basic web service functionality.

I am using Moodle 2.4 and think I have set up all permissions in plugins for web services correctly.

When I point my browser to the following url:

http://<my-moodle-site>/webservice/xmlrpc/server.php?wstoken=<token>&wsfunction=core_course_get_courses

I get an error:

faultCode630faultStringUnable to read request

Any help would be greatly appreciated.