// Make sure the mouse has been initialized
		if( !m_bInitialized )
			return FALSE;

		// Get the state of the mouse into the key buffer
		r = m_pMouse->GetDeviceState( sizeof(DIMOUSESTATE2), &m_dims2 );
		if( FAILED( r ) )
		{
			// If the device is not acquired...
			if( r == DIERR_INPUTLOST  || r == DIERR_NOTACQUIRED)
			{
				// ...then reacquire the device
				while( r == DIERR_INPUTLOST  || r == DIERR_NOTACQUIRED)
					r = m_pMouse->Acquire();

				if( SUCCEEDED( r ) )
					m_pMouse->GetDeviceState( sizeof(DIMOUSESTATE2), &m_dims2 );
				else
					return FALSE;
			}
			else
				// ...Otherwise it was some other error
				return FALSE;
		}

		// Check if the mouse was clicked
		if( key & 0x80 )
			return TRUE;
		else
			return FALSE;
 

First add the following to an appropriate header file#define MOUSE_LEFT	(0)	// Standard mouse buttons#define MOUSE_MIDDLE	(2)#define MOUSE_RIGHT	(1)#define MOUSE_LLEFT	(3)	// Left side on 5 button mouse#define MOUSE_RRIGHT	(4)	// Right Side on 5 button mouse#define MOUSEDOWN(name,button)(name.rgbButtons[button] & 0x80)#define MOUSE_DOWN(button)    (MOUSEDOWN(m_dims2,button))#define MOUSE_PRESS(button)   ((MOUSEDOWN(m_dims2,button) && !MOUSEDOWN(old_m_dims2,button)))#define MOUSE_RELEASE(button) ((!MOUSEDOWN(m_dims2,button) && MOUSEDOWN(old_m_dims2,button)))DIMOUSESTATE2 old_m_dims2