thank you very much

thanks for the reply.

but this one just give me the lower case until 0.

what I want it is very simple, I do not know if exist some sample code that transform one negative equation to 0, for ex:

y=ax+b

if y<0
y=0
else
y=y
end if

but I have a lote of this examples and will be nice if some simple equation like

y(y<0)=0

existe something like this?