In that example, we are loading in a separate JavaScript file named alert.js through the xmlhttprequest object. The alert.js file looks like this:

function showAlert() {
alert('hi there, I was loaded externally');
}

It is just a simple alert contained within a function. The guts of the procedure is contained I the importjs.js file so let us look at that in more detail. In particular we are interested in the load_js case:

We will take a look at that function on the next page.