Help me fix multiple lua installation (5.1 and 5.3)

Hi, previously i had install lua 5.1 . I tried to upgrade lua by installing lua 5.3 and now my system is weird. When i type "lua" in the terminal. I get "Lua 5.3.2 Copyright (C) 1994-2015 Lua.org, PUC-Rio". While if i type "qlua", i get "Lua 5.1 Copyright (C) 1994-2008 Lua.org, PUC-Rio".

Can you help me set my "lua" back to 5.1 ? Or qlua to 5.3 ? I need to use qlua. Thanks a lot for help.