average

#include <iostream>
using namespace std;

int main ()
{
int amount;
double result, value, tellen;
result = 0;

cout << "put in the amount of values you want the average of: ";
cin >> amount;
cout << endl;

for(tellen = 1; tellen <= amount; tellen++)
{
cout <<"Put in the " << amount << " number.";
cin >> value;
cout <<endl;
result + value = result; //what is wrong with this line?

}

cout << "The average is " << result/amount <<"." <<endl;

system ("pause");

return 0;
}

cout <<"Put in number " << tellen << " : ";