Some Questions about nntool...

Hi,

I have some questions about neural network in Matlab. I build a network using nntool about 6 month ago and now I need to know some information which I forgot and don't have a clue!

1) how can I know how many hidden neurons I chose? I know I chose 2 layers. tansig and purelin...

2) I chose LM training algorithm and don't have any idea about "iteration for net. structure", "learning coefficient or momentum coefficient" and "optimization of my network".

Is there anyone who can help me about my questions?

Thanks