Javascript add item to HTML collection

 insert before forms[1]:

forms[1].parentNode.insertBefore(newDiv, forms[1]);

insert after forms[1]:

// there is no insertAfter() so use the next sibling as reference element
forms[1].parentNode.insertBefore(newDiv, forms[1].nextSibling);

replace forms[1]:

forms[1].parentNode.replaceChild(newDiv, forms[1]);

https://stackoverflow.com/questions/8856281/how-to-add-an-element-into-the-htmlcollection-in-javascript