var SITE_PREFIX = "/";
var IMAGES_NAV_DIR = "images/nav/";

// mouseover preloads
var navImgOff = new Array();
var navImgOver = new Array();
var navImgOn = new Array();
if (document.images) {
    var navList = new Array('products_and_services', 'finds_and_retail', 'contact_us');
    for (var i=0; i<navList.length; i++) {
        navImgOff[navList[i]] = new Image();
        navImgOff[navList[i]].src = SITE_PREFIX+IMAGES_NAV_DIR+navList[i]+'-off.gif';
        navImgOver[navList[i]] = new Image();
        navImgOver[navList[i]].src = SITE_PREFIX+IMAGES_NAV_DIR+navList[i]+'-on.gif';
        navImgOn[navList[i]] = new Image();
        navImgOn[navList[i]].src = SITE_PREFIX+IMAGES_NAV_DIR+navList[i]+'-on.gif';
    }
}

// mouseover image functions
function navOff(navName) {
    if (navName && navName.length && document.images && document['nav_'+navName]) {
        if (navName == navActive) {
            // don't turn off current page's nav link
            document['nav_'+navName].src = navImgOn[navName].src;
        } else {
            document['nav_'+navName].src = navImgOff[navName].src;
        }
    }
}

function navOver(navName) {
    if (navName && navName.length && document.images && document['nav_'+navName]) {
        document['nav_'+navName].src = navImgOver[navName].src;
    }
}

function navOn(navName) {
    if (navName && navName.length && document.images && document['nav_'+navName]) {
        document['nav_'+navName].src = navImgOn[navName].src;
    }
}

// cookie functions
function setCookie(name, value, path, expires, domain, secure) {
    var curCookie = name + "=" + escape(value) +
      ((path) ? "; path=" + path : "") +
      ((expires) ? "; expires=" + expires.toGMTString() : "") +
      ((domain) ? "; domain=" + domain : "") +
      ((secure) ? "; secure" : "");
    document.cookie = curCookie;
}

function getCookie(name) {
    var dc = document.cookie;
    var prefix = name + "=";
    var begin = dc.indexOf("; " + prefix);
    if (begin == -1) {
        begin = dc.indexOf(prefix);
        if (begin != 0) return null;
    } else {
        begin += 2;
    }
    var end = document.cookie.indexOf(";", begin);
    if (end == -1) {
        end = dc.length;
    }

    return unescape(dc.substring(begin + prefix.length, end));
}

function deleteCookie(name, path, domain) {
  if (getCookie(name)) {
      document.cookie = name + "=" +
        ((path) ? "; path=" + path : "") +
        ((domain) ? "; domain=" + domain : "") +
        "; expires=Thu, 01-Jan-70 00:00:01 GMT";
  }
}

// random image
function insertRandomImage(imgPrefix, imgCount, imgSuffix, imgName, imgWidth, imgHeight) {
	var randomImage;
	var cookieName = 'last_'+imgName;
	var lastImage = getCookie(cookieName);
	randomImage = 1 + Math.floor(Math.random() * imgCount);
	while (randomImage == lastImage) {
		// don't repeat the same image twice in a row
		randomImage = 1 + Math.floor(Math.random() * imgCount);
	}
	document.write('<img name="'+imgName+'" id="'+imgName+'" src="'+imgPrefix+randomImage+imgSuffix+'" alt="" />');
	setCookie(cookieName, randomImage);
}