You have many things defined in the global scope, the better way is to define one global variable
app = {}, and then attach functions to it, like
app.init = function () {}
etc.

If somebody is changing your code and defines a function init or just a variable
init = "hi" (by mistake without putting var)
it will break the code

You don't have to change all the code now, but just keep it in mind for the future