DOMNode::insertBefore Adds a new child before a reference node &reftitle.description; public DOMNodefalseDOMNode::insertBefore DOMNodenode DOMNodenullchild&null; This function inserts a new node right before the reference node. If you plan to do further modifications on the appended child you must use the returned node. When using an existing node it will be moved. &reftitle.parameters; node The new node. child The reference node. If not supplied, node is appended to the children. &reftitle.returnvalues; The inserted node or &false; on error. &reftitle.errors; DOM_NO_MODIFICATION_ALLOWED_ERR Raised if this node is readonly or if the previous parent of the node being inserted is readonly. DOM_HIERARCHY_REQUEST_ERR Raised if this node is of a type that does not allow children of the type of the node node, or if the node to append is one of this node's ancestors or this node itself. DOM_WRONG_DOCUMENT_ERR Raised if node was created from a different document than the one that created this node. DOM_NOT_FOUND_ERR Raised if child is not a child of this node. &reftitle.seealso; DOMNode::appendChild