How to get screen resolution in C++?

Possible Duplicate:
How to get the Monitor Screen Resolution from an hWnd?

Is there a way to get the screen resolution in C++?
I have searched MSDN but with no luck. The closest thing I found was ChangeDisplaySettingsEx() but that doesn't seem to have a way to just return the res without changing it.

#include "wtypes.h"
#include <iostream>
using namespace std;

// Get the horizontal and vertical screen sizes in pixel
void GetDesktopResolution(int& horizontal, int& vertical)
{
   RECT desktop;
   // Get a handle to the desktop window
   const HWND hDesktop = GetDesktopWindow();
   // Get the size of screen to the variable desktop
   GetWindowRect(hDesktop, &desktop);
   // The top left corner will have coordinates (0,0)
   // and the bottom right corner will have coordinates
   // (horizontal, vertical)
   horizontal = desktop.right;
   vertical = desktop.bottom;
}

int main()
{       
   int horizontal = 0;
   int vertical = 0;
   GetDesktopResolution(horizontal, vertical);
   cout << horizontal << '\n' << vertical << '\n';
   return 0;
}

Source: http://cppkid.wordpress.com/2009/01/07/how-to-get-the-screen-resolution-in-pixels/