Jira script runner behavior is not working on forward and reforward screen

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Jira scriptrunner behaiour is not working

I have 3custome field select with drop dopwn otions
Fild 1 , Field 2, fileld3

Once select Fild1 then populate Fild2 values then select Fild2 value  then Fild3 values will get based on Fild2 selected value

And also I have “custome filed99” text value "define" or " Not define"

I needs to work on following 2 screens with condition
Forward screen and Reforwardscreen

Condition "fileld3” need to be none editmode if “custome filed99” value is = define or else fileld3 needs to be avalble for select options