Trying to use a variable between forms breaks all the thing

[Shelob9]

I'm trying to set a static variable in form one, and then use its magic tag as default value in from two. I get: Uncaught RangeError: Maximum call stack size exceeded in console from jQuery. There needs to be some way to get data between forms steps, since I can't use first form's magic tag or {get*} magic tag (since URL doesn't update) I was hoping static variables would carry through.