I'm trying to get a path tree of content with the following code - The problem that I seem to have is that @Model is null! What can I do to fix this it's driving me nuts. I just get 'Object reference not set to an instance of an object.' from the macro.

Can anyone offer me any help?

@using System.Web;
@using umbraco;
@using umbraco.interfaces;
@using umbraco.NodeFactory;

@{   
    var contentNode = new Node(-1);
    INode parentNode = @Model.Parent;
    var nodeTree = new List<Node>();
    
    Node globalRootNode = null;
    var globalNodeCollection = new List<INode>();
    Node globalContentItemNode = null;
    
    foreach (var n in contentNode.ChildrenAsList)
    {
       if (n.NodeTypeAlias == "GlobalContentContainer")
       {
           globalRootNode = new Node(n.Id);
           globalNodeCollection = globalRootNode.ChildrenAsList;
       }
    }

    while (parentNode != null)
    {
        nodeTree.Add(new Node(parentNode.Parent.Id));
        parentNode = parentNode.Parent;
    }

    nodeTree.Reverse();

    for (int i = 0; i < nodeTree.Count; i++)
    {
        foreach (var n in globalNodeCollection)
        {
            if (nodeTree[i].Name == n.Name)
            {
                globalContentItemNode = new Node(n.Id);
                globalNodeCollection = n.ChildrenAsList;
                return;
            }
        }
    }
  }
}