help !!concept of class templates

I have tried using a class template concept

but it does not seem to work ,
throws 2 error statements on compilation

i am new to the concept of class templates

what is the error in my program ???

/////
Error 663: "templ2.cpp", line 15 # Expected template arguments following template name 'student'.
void student::add()
^^^^^^^
Error 553: "templ2.cpp", line 31 # Expected type arguments to follow class template name.
student s1;

Code:

#include<iostream.h>
template <class T>
class student
{

   T rollno;
   T mark1;
   T mark2;

   public:
    void  add();  /* function prototype */

};
template <class T>
void student::add()
{
          T total;
          cout<<"enter the rollno of the student";
          cin>>rollno ;
          cout<<"enter the mark in the first subject ";
          cin>>mark1;
          cout<<"enter the mark in the second subject ";
          cin>>mark2;

          total = mark1 + mark2;
          cout<<" the total in the two subjects is "<<total;

          cout<<" the roll no is "<<rollno;

};

int main()
{
  student s1;
  s1.add();

  return 0;

}

Code:

template <class T>
void student::add()

This should be

Code:

template <class T>
void student<T>::add()

Also, when declaring an instance of this class it should not be like this:

Code:

student s1;

but this:

Code:

student<int> s1;

int, or whatever datatype you want T to be.