finding an element inside an element in js code example
Example 1: get elment by id within get element byclassname
var targetDiv = document.getElementById("foo").getElementsByClassName("bar")[0];
targetDiv.textContent = "Goodbye world!";
Example 2: javascript get all elements of an id
// You can't
// You can only have 1 instance of an id per document
// You need to use classes instead
var x = document.getElementsByClassName("example");