newbie ask for help about module development?

An exception occurred while I'm trying to write my module. This is a part of my .py file: class classroom(osv.osv): _name = 'course.classroom' _description = 'Classrooms' columns = { 'building' : fields.char('Building', size=64, required=True), 'room_num' : fields.char('Room Number', size=64, required=True), 'seats' : fields.integer(string='Seats', required=True), } And this for view.xml file: Classroomcourse.classroom

When I install the module, it prompt the message below: ParseError: "ValidateError The field(s) `arch, model` failed against a constraint: The model name does not exist or the view architecture cannot be rendered." while parsing file:///D:/Work%20Files/Project%20Files/workspace/openerp-8.0dev-20131208-000101/openerp/addons/course/course_view.xml:5, near Classroomcourse.classroom

I couldn't figure it out after spending a lot of time, could anyone help me? Thank u.