I am new with MS 5.0. I would like to create a system consist of a slab of water with 2 air spaces, which is similar to the expriment in the paper "Molecular Dynamics Study of Alkyl Benzene Sulfonate at Air/Water Interface: Effect of Inorgnic Salts", T. Zhao, et al, J. Phys. Chem. B 2010, 114, 5025-5033.

Could anyone show me how to construct that model?