it my first post.

As I see, this form is helpful for the pleople who needs help on many topics.

Before talking about my problem, I would like to say I can code some programs in Visusal Basic 6.0, Matlab and Maple.

I have coded a program in Maple, but I have just learned that Mathematica draws much more better in 3D when compared to Maple.

So , I need to code the same program in Mathematica.

May I please get some information about the following topics:

- How to write a 'for next' loop?
- How to load values in to a double sequence (or a matrix, i.e. x(m,n) for m=1,2,...,20 and n=1,2,...,10)?
- How to plot a double sequence on 3D (with the form [m,n,x(m,n)])?

**Note**. If it could help I can also write the Maple codes.