How do u go up and down stairs?

i am playing the 6395fb5(tiled version) of cataclysm and i can’t find out how to go up or down stairs.

please help?

? key provides a help menu, including a guide to buttons. Using tileset for early play is… unadvisable, because in ASCII you can’t have the question because the keys to move between z-levels are the same as the stairs’s symbol, < and > respectively.