Implementing Scrollbars: Step 2

Modify the EZFUNC.H file to add global variables and the prototype for a function that aids in calculating scroll ranges and positions.

The function prototype should appear as follows:

/* Use this function to interpret the WM_SIZE message's client area parameters */
void CalcClientMetrics (HWND hWnd, 
                        int *nClientWidth, 
                        int *nClientHeight, 
                        int *nRightBarThickness, 
                      int *nBottomBarThickness);

The global variables should appear as follows:

int XScrollRange, YScrollRange; /* Scrollbar ranges */
int XScrollPosition, YScrollPosition; /* Scrollbar positions */