Also it is #include <string> AFAIK
Also you should umm work on your class it looks completely wrong to me. I don't even see the closing brace to it or even the class object... all I see is public: then the "out of scope" declarations but you never initialize the functions inside the class or end the class.
Also please use code tags
or the <> button ( on the right when submitting and the bottom when editting.
don't want to be mean or anything but you should read the error messages before posting =p
I'm sure you are getting an error with your class for starters you are missing the semi-colon at the end which your compiler will flag an error on.
ok first of all you forgot the semi colon after the class def. secondly remove the marks:: on everything. its already in the scope of the class. thats what marks does so i cant remember if thats going to cause an error or its just redundant and finally you never gave grade an initial value which will def cause an error