var formChilds = form.childNodes;
var elm = document.creatElement('input');
// up to this point eclipse knows what kind of object 'elm' is, and offers automatic completion of properties, like elm.nodName etc.

foreach(var elm as formChilds){
  elm = childs[elm];
  // from here on eclipse does not know of which type the object 'elm' is and no auto completion is available
//(...)