[Dev-C++] How do I declare a template class variable and make an instance seperately?

[Chris I. <chr...@li...>]

Hello all :)
Hopefully someone can shed some light on this problem I'm having.  I'm
trying to declare a variable to a type of class I've defined (which is
a minHeap), but actually instantiate it later when I get a command from
the user.  This is my class and if you look down a lil you can see what
I'm trying to do in my main().  I want to ask for the size from the
user, but when I try to I can't get my code to compile.  Here is the
class definition and the constructor.  This is the error I'm getting.

/Users/ci/minheap/minheap.h:42: error: prototype for 'HEAP<T>::HEAP()'
does not match any in class 'HEAP<T>'

I've been reading up on smart pointers but i'm not sure if that's what
I'm suppose to be using.  Any help/info would help me alot.......
THANKS

#-------------------------------------------------------------
#include <cstdlib>
#include <iostream>
using namespace std;

struct ELEMENT{int key;};

template<class T>
class HEAP {
   public:
        HEAP(int n);
        ~HEAP(){ delete [] heap;}
        T Min(){if (CurrentSize == 0)
                                throw OutOfBounds();
                        return heap[0];}

        HEAP<T>& Insert(int k);
        int DeleteMin();

        void printHeap() const;

   private:
        int CurrentSize, Capacity;
        T *heap;                                // element array

};

template<class T>
HEAP<T>::HEAP(int n){                             //constructor.
        Capacity    = n;
        cout << "Heap's Capacity is: " << Capacity << endl;
        heap        = new ELEMENT[Capacity];
        CurrentSize = 0;
}

int main(void){

HEAP<ELEMENT> A(10);     //THIS WORKS FINE
HEAP<ELEMENT> B;          // I CAN'T DO  THIS THOUGH...why?? how can
I??

int size;

cout << "Give the desired size of this heap: " << endl;
cin >> size;
B(size);                      // I WANT TO INSTANTIATE B DOWN HERE
}