Tweaking a neural network

Hi

I am wishing to create a neural network with inputs (20), hidden layer one (9 neurons), hidden layer two (8 neurons) and output (1)

I have used the GUI nftool to setup a neural network with inputs (20), one hidden layer (9 neurons) and output (1)

I have printed off the advanced script and wish to tweak it to accommodate what I want..............

Can somebody help me do the tweaking?

Thank you

Bob M