How to prevent gallery type change?

[User (Legacy)]

Hi! 

I need to prevent users from changing chart's gallery to some types (eg 

Curve) if some conditions are not met and display a message box stating what 

is wrong instead. 

I handle ChangeType event and tried to set Result to 0 or 1 with no luck - 

the ChartFX seems to fire this event _after_ it has changed the gallery. 

How can I cancel the gallery change? 

Thanks 

Serge