how to append a css class to an element by javascript?

Question

Suppose a HTML element\'s id is known, so the element can be refereced using:

document.getElementById(element_id);

Does a nati

Answer 1

you could use setAttribute.

Example: For adding one class:

 document.getElementById('main').setAttribute("class","classOne"); 

For multiple classes:

 document.getElementById('main').setAttribute("class", "classOne classTwo");