Javascript - Loop through child elements and change its class

gistfile1.txt

	/*
	**
	** Steps
	**
	*/
	var steps = document.getElementById('steps');

	steps.firstElementChild.classList.toggle('active');
	
	var children = steps.children;

	var i = 0;

	function removeActive() {
		// Remove all active child
		for (var index = 0; index < children.length; index++) {
			children[index].classList.remove('active');
		}

		i += 1;
		
	}

	function changeActive() {
		
		removeActive();

		if ( i < children.length) {
			
			children[i].classList.add('active');

		} else {

			if (i == children.length ) {

				steps.firstElementChild.classList.add('active');
				i = 0;

			}

		}

	}
	
	document.querySelector('button.next').addEventListener("click", changeActive, false)