Code that worked previously no longer working

I have a form, "Form A" that I created a few months ago. On Form A, I have image buttons set to "Hidden" that will either stay hidden or will display based on a variable "Total" field.

I have created a new form, "Form B," where I've attempted to do the same thing: insert image buttons set to "Hidden" that either stay hidden or toggle to visible based on a variable in the "Total" field.

I cannot get Form B to do the same thing that Form A does. I have even changed the image button names and changed the Total field to the exact same settings in Form B that I had in Form A- and it doesn't work in Form B, though it still works in Form A. I have even copied the image buttons containing the JavaScript from Form A and pasted them into Form B. But the debugger on Form B shows me syntax and XML naming errors.

Has this happened to anyone else?

Best regards,

Christine