The Ext framework is built using object-oriented (OO) concepts common to other languages like C#, Java, etc., but not common to traditional JavaScript development. If you're used to the hodgepodge of global functions and variables common to other JavaScript libraries/code snippets, development with Ext will require a different mindset. It might seem difficult at first, but the payoff will be well worth the effort.
If you are unfamiliar with OO concepts or how they are applied to JavaScript, you might first begin by reading through some OO JavaScript resources. Of course, Ext itself is also an excellent template for how to develop OO JavaScript, so don't be afraid to dive into the Ext code and see how it does things!
