if(!window.Node){
  var Node = {ELEMENT_NODE : 1, TEXT_NODE : 3};
}

function checkNode(node, filter){
  return (filter == null || node.nodeType == Node[filter] || node.nodeName.toUpperCase() == filter.toUpperCase());
}

function getChildren(node, filter){
  var result = new Array();
  var children = node.childNodes;
  for(var i = 0; i < children.length; i++){
    if(checkNode(children[i], filter)) result[result.length] = children[i];
  }
  return result;
}

function getChildrenByElement(node){
  return getChildren(node, "ELEMENT_NODE");
}

function getFirstChild(node, filter){
  var child;
  var children = node.childNodes;
  for(var i = 0; i < children.length; i++){
    child = children[i];
    if(checkNode(child, filter)) return child;
  }
  return null;
}

function getFirstChildByText(node){
  var val = getFirstChild(node, "TEXT_NODE");
  if(val.nodeValue.replace(/^\s+|\s+$/g, ''))
  {
    return val;
  }
  return false;
}

function getNextSibling(node, filter){
  for(var sibling = node.nextSibling; sibling != null; sibling = sibling.nextSibling){
    if(checkNode(sibling, filter)) return sibling;
  }
  return null;
}
function getNextSiblingByElement(node){
        return getNextSibling(node, "ELEMENT_NODE");
}