missing varaiables for grid build under windows?

winsrc/gui.cpp

@@ -33,6 +33,7 @@ void dbp(char *str, ...)
 
 int GraphBuffer[MAX_GRAPH_TRACE_LEN];
 int GraphTraceLen;
+int PlotGridX, PlotGridY;
 
 HPEN GreyPenLite, GreyPen, GreenPen, WhitePen, YellowPen;
 HBRUSH GreenBrush, YellowBrush;