Overlapping Scatter Plot pts

[User (Legacy)]

I'm using ChartFX 98, VC++.  I'm plotting a series of 16 XY data points. 

Every time I write a new series, the old data points disappear. 

Q: How can I write a new set of data points over the old, such that the old 

AND new are still visible ?   I don't want to add a new series for this, can 

I do it another way? 

Thank You, anyone