(PHP 4 >= 4.1.0)
DomNode::previous_sibling — Returns the previous sibling of node
This function returns the previous sibling of the current node. If there
is no previous sibling it returns FALSE
(< 4.3) or NULL
(>= 4.3). You
can use this function to iterate over all children of a node as shown in
the example.
See also domnode_next_sibling().