How to make this solid?

 From:  Koi
10782.18 
Hey Brian and Michael,
I thank you so much! I love to learn how MoI and Nurbs are going!
I got your points.
I tried to make it solid with network aswell, but this was not possible, because I did not take a second profile on the sides to prevent overlapping?
Thanks so much, thid forum makes it defintely bigger!

thanks a lot,
Koi