Workflow Script to Reload a Form with Saved Field Values for Selected Fields

I'm new to Creator, and Deluge, and I'm trying to develop a workflow which I thought would be basic, but I need some help.

When a user inputs values to one of the forms I've designed, I want the user to be able to select certain fields that do not reset their input values when the form is Submitted.

Is there a field property somewhere that I can set so the form reloads with the last input value? Or must this be done with variables by storing the user's input during Validation and then retrieving the value during form Load?

If by variables, could someone direct me in the simplest way to get started with this? I created a Decision Box to correspond to each text input field, so that when checked True by the user, the corresponding text field will store its value in a variable. But I am completely unclear about Deluge syntax for declaring and setting variables.

For Example, On Add - Validate

if (input.Save_Room==True)
{
RoomSave = true;
RoomSaved = input.Room;
}

But when I try to write code to pass these variables' values back into the fields during the On Add - On Load, I get errors.

input.Room = RoomSaved;

!Variable RoomSaved is not defined

I've read the Deluge help guide for declaring variables, but this doesn't seem to be in the help file. Any help would be quite appreciated.