var modifier = 5;
var stringPosn = 4;

var ctaNavLibrary = new Array();
ctaNavLibrary[0] = "summary";
ctaNavLibrary[1] = "imgs";
ctaNavLibrary[2] = "multimedia";
ctaNavLibrary[3] = "riders";
ctaNavLibrary[4] = "offerform";
ctaNavLibrary[5] = "relatedsites";

var whereRwe = this.location.href;
var locArray = whereRwe.split("/");
var theSection = locArray[stringPosn];
var setSection = -1
for(i = 0; i < ctaNavLibrary.length; i++){
	if(ctaNavLibrary[i] == theSection){
		setSection = i;
	}
}

if(setSection != -1){
	setSection = setSection + modifier;
	activeSection = theSection;
	document.images[theSection].src = navCtaActive[setSection].src;
}