tree implementation using linked list,with parent pointer,first chil pointer and siblings pointer in c

Question

I want help in linked list implementation of a tree. A tree node has three child. using pointers: Parent, Siblings and FirstChild.

I have tried making it but couldn't get it to work. I need help in inserting new nodes

void InsertFirstChild(Node newNode)
{
    newNode.m_Parent = this;
    newNode.m_NextSibling = m_FirstChild;

    if (m_FirstChild != null)
        m_FirstChild.m_PrevSibling = newNode;
    else
        m_LastChild = newNode;

    m_FirstChild = newNode;
}