php - Make value=null when page first loads

Is it possible to remove a value whilst the page is loading?

I'm using OSClass, and on one of the pages it's by default adding a value for region (cambridshire):

I need to clear this value since it's causing problems, everytime I type something else in, by default, it registers it as Cambridgeshire...

If I look at code for it:

It's being generated by a function (can see my JQuery attempt to clear it which hasn't worked).

Then if I search the function is splits up in many different parts, so I don't know where to go from there.

Basically, is there a way to remove the value when page loads and save the new value when the user submits?

JSFiddle - Note it won't display anything due to the way code is generated