JavaScript get parent element and write holder div for siblings

Answer 1

Seeing as this has to be JavaScript (and not jQuery) and you can only indentify the child1 by id you could do something as crude as this:

var child1 = document.getElementById("child1"),
    parent = child1.parentNode,
    contents = parent.innerHTML ;
    parent.innerHTML = '
' + contents + '
';

Hope this helps...