randomize 0.5
N=15
dim a(N,2)

for i = 0 to N-1
    a(i,1)= int(i/5)
    a(i,2)= int(rnd(1)*5)
next

print "Unsorted by column #2"
print "by construction sorted by column #1"
for i = 0 to N-1
    print a(i,1), a(i,2)
next

sort a(), 0, N-1, 2
print

print "After sorting by column #2"
print "Notice wrong order by column #1"
for i = 0 to N-1
    print a(i,1), a(i,2),
    if i=0 then
        print
    else
        if  a(i,2) = a(i-1,2) AND  a(i,1) < a(i-1,1) then print "bad order" else print
    end if
next