var defaultStatus = '';
	var preOn;
	var preOff;
	
		function roll_highlight() {
			if (!isOn(this.src)) {
				prefix = this.src.substring(0,this.src.lastIndexOf("/")+1);
				postfix = this.src.substring(this.src.lastIndexOf("/")+3);
				this.src = prefix+preOn+postfix;
				if (this.alt) {
					window.status = this.alt;
				}
			}
			return true;			
		}
		
		function isOn(imgsrc) {
			onstr = imgsrc.substring(imgsrc.lastIndexOf("/")+1,imgsrc.lastIndexOf("/")+3);
			if (onstr.toLowerCase()==preOn) {
				return true;
			}
			return false;
		}
		
		function roll_shadow() {
			if (isOn(this.src)) {
				prefix = this.src.substring(0,this.src.lastIndexOf("/")+1);
				postfix = this.src.substring(this.src.lastIndexOf("/")+3);
				this.src = prefix+preOff+postfix;
				if (this.alt) {
					window.status = defaultStatus;
				}
			}
			return true;			
		}
	
		function initRollWinter(ds) {
			makeItRoll(ds, "w_", "z_");
		}

		function initRollSummer(ds) {
			makeItRoll(ds, "z_", "w_");
		}

	
		function makeItRoll(ds, preOff, preOn) {
			this.preOn = preOn;
			this.preOff = preOff;
			if (ds!=null) {
				defaultStatus = ds;
				window.status = defaultStatus;;
			}
			images = document.getElementsByName("rollover");

			for (i=0;i<images.length;i++) {
				images[i].onmouseover = roll_highlight;
				images[i].onmouseout = roll_shadow;
			}
			
			return true;
		}