add attribute to element javascript code example
Example 1: javascript change attribute
var element = document.getElementById("elemId");
element.setAttribute("attributeName", "value");
Example 2: set attribute javascript
Element.setAttribute(name, value);
Example 3: put new attribute on html tag using javascript
span.setAttribute("style", "width:110%;float:center;left-margin:-10px;top-margin:-10;");
Example 4: set property dom javascrpt
document.getElementsByTagName("H1")[0].setAttribute("class", "democlass");