if/elseif/else statements control the execution of chunks of code. Like chunks, if statements can be nested. The same rule for scope applies to nested if statements as it does to nested chunks. The following code demonstrates the use of nested if statements:

print ("Enter a number")
x = io.read()

if x == "6" then
    print ("x is six!")

    print ("Enter another number")
    local y = io.read()
    -- Nested if statement begins here
    if y == "6" then
        print ("y is also six!")
    elseif y == "5" then
        print ("y is one less than x")
    else
        print ("x is 6, but y is not!")
    end
    -- Nested if statement ends here
else 
    print ("x is not 6!" .. x)
end