// --- image swap functions:
function newImage(arg) {  
     if (document.images) {
          rslt = new Image();
          rslt.src = arg;
          return rslt;
     }
}

function changeImages() {
     if (document.images && (preloadFlag == true)) {
          for (var i=0; i<changeImages.arguments.length; i+=2) {
               document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
          }
     }
}

// --- image preloader function:
var preloadFlag = false;
function preloadImages() { 
	if (document.images) { 
		//top nav menu:
		homeon = newImage("images/top_nav/home_on.gif");
		whatsnewon = newImage("images/top_nav/whats_new_on.gif");
		ouradventureson = newImage("images/top_nav/our_adventures_on.gif");
		privateadventureson = newImage("images/top_nav/private_adventures_on.gif");
		familyadventureson = newImage("images/top_nav/family_adventures_on.gif");
		whyincaon = newImage("images/top_nav/why_inca_on.gif");
		aboutincaon = newImage("images/top_nav/about_inca_on.gif");
		alaskaon = newImage("images/top_nav/alaska_on.gif");
		antarcticaon = newImage("images/top_nav/antarctica_on.gif");
		galapagoson = newImage("images/top_nav/galapagos_on.gif");
		patagoniaon = newImage("images/top_nav/patagonia_on.gif");
		peruon = newImage("images/top_nav/peru_on.gif");
		turkeyon = newImage("images/top_nav/turkey_on.gif");
		preloadFlag = true;
	}
}

// Photo Gallery pages pop-ups:
function popup(theURL,winName,features) { //v2.0
  window.open(theURL,winName,features);
}