需要以编程方式创建sharepoint字段

I am using a standard sharpoint form, I have code that displays a tracking number once the user selects "completed" on the "Status" dropdown. All of it functions, what i need to do at this point is make the tracking number required once they select completed. If i make the field required via sharepoint and then try to hide it sharepoint will not save the task :/ Here is my code:I am using a standard sharpoint form, I have co