//preload images for navigation
var port = new Image();			port.src = "../nav/port.gif";
var bio = new Image();			bio.src = "../nav/bio.gif";
var media = new Image();		media.src = "../nav/media.gif";
var contact = new Image();		contact.src = "../nav/contact.gif";
var forsale = new Image();		forsale.src = "../nav/forsale.gif";
var rentals = new Image();		rentals.src = "../nav/rentals.gif";
var credits = new Image();		credits.src = "../nav/credits.gif";
var portOn = new Image();		portOn.src = "../nav/port-on.gif";
var bioOn = new Image();		bioOn.src = "../nav/bio-on.gif";
var mediaOn = new Image();		mediaOn.src = "../nav/media-on.gif";
var contactOn = new Image();	contactOn.src = "../nav/contact-on.gif";
var forsaleOn = new Image();	forsaleOn.src = "../nav/forsale-on.gif";
var rentalsOn = new Image();	rentalsOn.src = "../nav/rentals-on.gif";
var creditsOn = new Image();	creditsOn.src = "../nav/credits-on.gif";

function swapImageOn(x){ $(x).src = '../nav/' + x + '-on.gif'; }

function swapImageOff(x){ $(x).src = '../nav/' + x + '.gif'; }