adding node to html code example
Example 1: add element to body javascript
var elem = document.createElement('div');
elem.style.cssText = 'position:absolute;width:100%;height:100%;opacity:0.3;z-index:100;background:#000';
document.body.appendChild(elem);
Example 2: javascript append to paragraph
// In the JS script
var parElement = document.getElementById("myPar");
var textToAdd = document.createTextNode("Text to be added");
parElement.appendChild(textToAdd);
//In the HTML file
<p id="myPar"></p>