global stack$
stack$=""

randomize .51
for i = 1 to 10
    if rnd(1)>0.5 then
        print  "pop => ";pop$()
    else
        j=j+1
        s$ = chr$(j + 64)
        print "push ";s$
        call push s$
    end if
next

print
print "Clean-up"
do
    print  "pop => ";pop$()
loop while not(empty())
print "Stack is empty"

end

'------------------------------------
sub push s$
    stack$=s$+"|"+stack$    'stack
end sub

function pop$()
    if stack$="" then pop$="*EMPTY*": exit function
    pop$=word$(stack$,1,"|")
    stack$=mid$(stack$,instr(stack$,"|")+1)
end function

function empty()
     empty =(stack$="")
end function