Code

function onNodeClicked(sender, args)
{
	var node = args.getNode();

	// find in / parent nodes
	var inLinks = node.getIncomingLinks();
	for (var i = 0; i < inLinks.length; i++)
		console.log(inLinks[i].getOrigin().getText());

	// find out / child nodes
	var outLinks = node.getOutgoingLinks();
	for (var i = 0; i < outLinks.length; i++)
		console.log(outLinks[i].getDestination().getText());
} 

Code

// all at once
var allLinks = node.getAllLinks();
for (var i = 0; i < allLinks.length; i++)
{
	var link = allLinks[i];

	// print the other end
	if (link.getOrigin() == node)
		console.log(link.getDestination().getText());
	else
		console.log(link.getOrigin().getText());
}