Answers for "how to insert before element in js"

javascript add div before element

var my_elem = document.getElementById('my_id');

var span = document.createElement('span');
    span.innerHTML = '*';
    span.className = 'asterisk';

my_elem.parentNode.insertBefore(span, my_elem);

javascript insert before

function insertBefore(newNode, existingNode) {
    existingNode.parentNode.insertBefore(newNode, existingNode);
}