adding alert to oscillator

["Shrikant Agrawal" <vvsamiti@xxxxxxxx>]

I have been using the following with 2000i
It plots as a histrogram with red and green bars
I wish to generate a sell signal when it turns red from green and vice versa
I want to add double sell/buy signal if the oscillator crosses zero line
 sell when going down and buy when coming up.)
I tried many times but failed
can anyone help
thanks in advance
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VALUE1  = average((h+l)/2,34);
VALUE2  = average((h+l)/2,5);

VALUE3 = VALUE2 - VALUE1;

if VALUE3 > VALUE3[1] then begin
 plot1(VALUE3,"Green");
end;

if VALUE3 < VALUE3[1] then begin
 plot2(VALUE3,"Red");
end;
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