I am writing a function which will check if the letter is in upper case , if so it returns true otherwise false.
Following is the code, I have written, but what is wrong?

#include<iostream>

using namespace std;

using std::cout;
using std::cin;
using std::endl;

int isUpperCase ( char );

int main()

{
int i;
char c;

cout<<"Enter a charactor : ";
cin>>c;

i = int ( c );

isUpperCase ( i );


return 0;


}

int isUpperCase ( i )

{
if ( i > 65 && i < 90 )

return 1;

else

return 0;

}

please comment.