Line 10: We want to create a JavaScript object to load the xml file into. We could just load into the document.body, but using a container is far more flexible as you can then position imported xml data anywhere you like. To this end we create a variable named el and point it to the document.getElementById(args[2]) statement. The argument in the statement will allow us to later specify which element we want to load the data into. We could have just used document.getElementById('contentLYR') where contentLYR would be a block element in the document body (usually a div tag) with an id value of contentLYR. And that would be perfectly acceptable in a lot of instances. However later on we are going to do some multiple data loading into different containers in the document so we want as much flexibility as possible.

Line 11: The next thing we want to do is actually place the data into an element. I find