problem with function overloading

[DANNY123]

I don't know why the compiler always says the 8 `double poly<double>::x' is private
and
36 for `T poly<T>::power(int, T)' does not match any in class `poly<T>'

#include <iostream>
T x is unaccesible.

using namespace std;

template<typename T>
class poly
{private:
     T x;
int n;
int a;

public:

 poly(const T x1,const int a1,const int n1)
 {  n=n1; 
    x=x1;
     a=a1;
     
}              
T power(const int &n,const  T &x);
 poly&operator+(poly&p1);
void display();
~poly();


};
template<typename T>
void poly<T>::display()
{
     cout<<x;
     };
     

template<typename T>
 T poly<T>::power(int n, T x)
 {         int i=0;
             L: if(i==n)
                 goto M;
                 x=x*x;
             i++;
             
             M:return x;
             };
 template<typename T>
poly<T>&poly<T> ::operator+( poly<T>&p1 )
{     
        x=p1.x+x;
        return this;
        }
             

int main()
{    
     poly<double> P(2.5,1,2);
    P.x=P.power(2,2.5);
    P.display();
     
    
    system("pause");
    return 0;
}

[Smac89]

I don't know why the compiler always says the 8 `double poly<double>::x' is private

{private:
     T x;
int n;
int a;

`T poly<T>::power(int, T)' does not match any in class `poly<T>'

T power(const int &n,const T &x);

[DANNY123]

#include <iostream>
using namespace std;

template<typename T>
class poly
{private:
     T x;
int n;
int a;

public:
	poly()
	{
		this->x=0;
		this->a=0;
		this->n=0;}
 poly(T x1,int a1, int n1)
 {  n=n1; 
    x=x1;
     a=a1;
     
}              
void power();  
 poly&operator+(poly&);
void display();
~poly()
{};


};
template<typename T>
void poly<T>::display()
{
     cout<<x;
     };
     

template<typename T>
 void poly<T>::power()
 {         int i=0;
             L: if(i==n)
                 goto M;
                 x=x*x;
             i++;
             
             M: x=a*x;
             };
 template<typename T>
poly<T>&poly<T> ::operator+( poly<T>&p1 )
{     
        x=p1.x+x;
        return this;
        }
             

int main()
{    
     poly<double> P(2.5,1,2);
	 P.power();
   
    P.display();
     
    
    system("pause");
    return 0;
}