[ALPS-users] How can we visualize a lattice in ALPS?

Dear All I want to make a new lattice, but before serious calculation, I like to see the lattice. I searched in the alps mailing list and I found that probably "lattice-preview" should be a tool for visualization of lattices in ALPS. But I have two problem: first, when simply I type "lattice-preview" in the terminal I receive the following error: /opt/alps/bin/lattice-preview: 30: /opt/alps/lib/python/alps/preview.py: Permission denied Is there anyone to know why I receive the error? second, If we suppose the "lattice-preview" works well, what is the input file for this program? thanks in advanced Kaveh Edalat