EL- why is one not working, when its counterpart is working ?!

["Romi Ghose" <r.ghose@xxxxxxxxxxx>]

if datacompression<2 and date=lastcalcdate then begin

value1=iff(high>value1[1],high,value1[1]);    {high of the last trading
}    - this guy works
value2=iff(low<value2[1],low,value2[1]);    (low of the last trading
     - this guy does not work

plot1(value1);    - works
plot2(value2);    - does not work

end;

last trading day or not, value2 returns zero.  Am I missing something?