// ' IMAGE PRELOAD FUNCTION
function imgPreload () {
	for (i = 0; i < arguments.length; i ++) {
		preloader = new Image();
		preloader.src = "images/" + arguments[i];
	}
}

// ' CALL TO IMAGE PRELOAD FUNCTION
// ' (image filenames including extensions are passed as arguments (comma-separated strings))
imgPreload("nav_contact_mo.gif","nav_forms_mo.gif","nav_lenses_mo.gif","nav_practice_mo.gif","nav_services_mo.gif","nav_email_mo.gif","nav_home_mo.gif");


// ' IMAGE SWAP FUNCTION
function imgSwap (theImg) {
	if (theImg.src.indexOf("_mo.") == -1) {
		imgSrcSplit = theImg.src.split(".");
		imgExt = imgSrcSplit.pop();
		newSrc = imgSrcSplit.join(".") + "_mo." + imgExt;
	} else {
		imgSrcSplit = theImg.src.split("_mo.");
		newSrc = imgSrcSplit[0] + "." + imgSrcSplit[1];	
	}
	theImg.src = newSrc;
}


// ' COOKIE SET AND GET FUNCTIONS
// ' SIMPLISTIC SINGLE UNESCAPED VALUE


function setCookie(cookieName, cookieValue) {
	var nextyear = new Date();
	nextyear.setFullYear(nextyear.getFullYear() + 1);
	document.cookie = cookieName + "=" + cookieValue + ";path=/;expires=" + nextyear.toGMTString();
}

function getCookie(cookieName) {
	var allcookies = document.cookie;
	var pos = allcookies.indexOf(cookieName + "=");
	if (pos != -1) {
		var start = pos + cookieName.length + 1;
		var end = allcookies.indexOf(";", start);
		if (end == -1) {
			end = allcookies.length;
		}
		var value = allcookies.substring(start, end);
		//' alert("value = " + value);
		return value;
	}
}