Adding and Removing Rules
stylesheet.insertRule(".have-border { border: 1px solid black;}", 0);Changing Element Styles
function colorElementRed(id) { var el = document.getElementById(id); el.style.color = "red"; }function changeElement(id) { var el = document.getElementById(id); el.style.color = "red"; el.style.fontSize = "15px"; el.style.backgroundColor = "#FFFFFF"; }