My first dose..

First thing,global javascript variables can be referenced directly through the window reference. The variables become part of the window's properties.
Second, apparently I read that you could use the Image object in javascript to load a servlet by passing the servlet url as a parameter. I will give this a try later.
Third, when trying to think of a solution design for an issue or enhancement, approach it like a math problem. Look at what's given. Next, look for what can be derived using the given. Lastly, try to produce what's needed when none of the two are present.
Lastly, I've realized that I've learned very little in the last three years of my career. If there is anyone to blame for this, it's me (and my old company perhaps? haha) . Understand the concept of how the technology works. Understand and remember.