Need help with On Edit - On Load criteria scripting

Need help with On Edit - On Load criteria scripting

I've implemented a criteria script where my selection of dropdown1 filters the possible selections of dropdown2.
I am trying to create a script for the On Edit - On Load condition that behaves as such:

I would click edit for a record that had been previously created. That record would open with my earlier selections still intact. My goal is to change dropdown2. If I open dropdown2 I see every selection, even those that do not match the criteria as determined by dropdown1. The only way to have dropdown2 filter according to the criteria is to change the selection in dropdown1 to something different and then back to the correct selection. This runs the script again.

Script used...
Series
      On User Input

  1. if (count(Content_Type[Series == input.Series])  ==  0)
  2. {
  3.     clear Type_Name;
  4. }
  5. else
  6. {
  7.     rec_TYPE  =  Content_Type  [Series == input.Series] sort by  Type ;
  8.     Type_Name:ui.add(rec_TYPE.Type.getall());
  9. }
  10. if (count(Tour_League_Division_Conference[Series == input.Series])  ==  0)
  11. {
  12.     clear Tour_League_Division_Conference_Name;
  13. }
  14. else
  15. {
  16.     rec_TLDC  =  Tour_League_Division_Conference  [Series == input.Series] sort by  Name ;
  17.     Tour_League_Division_Conference_Name:ui.add(rec_TLDC.Name.getall());
  18. }

What script can I write for the On Edit - On Load condition so that dropdown2 shows only the selections that were specified by dropdown1 AND keeps the original selection made when the record was originally created? 

Thanks,
Brent