mask and proper index

[Peter Otten]

Diego Avesani wrote:

> If I can ask, due to the fact that I am new to thins kind of forum.
> In this moment, I have another problem related to the data I am working
> on. Should I write another post? 

You should start a new thread for a new problem, even if for you it is part 
of the same project or script.

> Should I do something else related to this post?
 
Telling us that your problem is solved is nice. If you have to modify a 
proposed solution or found a better one elsewhere you should also mention 
that for further reference. I think you already did that with

> You understood perfectly what was my problem. Thanks a lot, indeed it 
seems to work.

No further action needed :)