Iterating through list box

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1

Hello,

I need to deal with list box on web page. There is about 4 positions to pick, and for each one another actions have to been performed before changing to option 2 from list box. Do you have any good practices how should it be solved in a sequence?

Should I make an array/list with predefined options to choose or there is other methodology to work with list boxes?

Regards,