Using MouseProc callback function as a class member function

//class declaration
//...
private:
LRESULT CALLBACK MouseWndProc(int nCode, WPARAM wParam, LPARAM lParam);
//...

SetWindowsHookEx(WH_MOUSE, (HOOKPROC)MouseWndProc, //...

//declaration
class MyClass
{
public:
void MyClass();
void ~MyClass();
static LRESULT CALLBACK MouseWndProc(int nCode, WPARAM wParam, LPARAM lParam);

private:
int x;
int y;
};
//and implementation:

LRESULT CALLBACK MyClass::MouseWndProc(int nCode, WPARAM wParam, LPARAM lParam)
{
switch(wParam)
	{
	case WM_MOUSEMOVE:
		{

		x = pMouseStruct->pt.x;
		y = pMouseStruct->pt.y;
		break;
		}

	}
	return CallNextHookEx(hhk, nCode, wParam, lParam);
}

x = pMouseStruct->pt.x;
y = pMouseStruct->pt.y;

Member MyClass::x cannot be used without an object
Member MyClass::y cannot be used without an object