(PHP 4 >= 4.1.0)
DomNode->first_child — Returns first child of node
Returns the first child of the node.
(PHP >= 4.3 only) If no first child is found, NULL is returned.
See also domnode_last_child(), and domnode_next_sibling(), domnode_previous_sibling().
in PHP5's DOM (Not DOM-XML) class use firstChild variable instead of first_child() function.