//// image replacement ////

// set variables
var imgDir = 'content/images/nav/';
var imgOff = '-off.gif';
var imgOn = '-on.gif';

/* cache images - listed as arguments in the function call */

//	 returns an image cache object
function imgCache() {
	this.onImgs = new Array(arguments.length);
	this.offImgs = new Array(arguments.length);
	for (i = 0; i < arguments.length; i++) {
		onImgs[arguments[i]] = new Image();
		offImgs[arguments[i]] = new Image();
		onImgs[arguments[i]].src = imgDir + "lnk-"+ arguments[i] + imgOn;
		offImgs[arguments[i]].src = imgDir + "lnk-"+ arguments[i] + imgOff;
	}
	return this;
}

// generic image rollover function
function imgChange(imgName, state) {
	if (state){
		document[imgName].src = onImgs[imgName].src;
	}
	else {
		document[imgName].src = offImgs[imgName].src;
	}
}

// Hard coded img caching - not keen!
imgCache("home","b2b","data","services","resources","clients","about");