HR Help Desk Field Read Only based on Category Name

Summary:

Expression that will make a field read only unless a certain category name is selected

Content (required):

Hi There, just wondering if anyone had an example Expression that could be used to say a field (Affected Party) is read only unless a Certain Category Name is selected? Would it be something similar to the below

if((getAttribute("CategoryName") == "STAFF_MANAGEMENT_ISSUES")

{return false;} else {return true;}

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