function navOver() {
	if (this.originalSrc == undefined) this.originalSrc = this.src;
	this.src = this.src.split("_on.gif").join("").split(".gif").join("") + "_on.gif";
}

function navOut() {
	if (this.originalSrc != undefined) this.src = this.originalSrc;
}

function initialize() {
	ids = ["about", "portfolio", "fabrics", "contact"];
	for (i in ids) {
		document.getElementById("nav_" + ids[i]).onmouseover = navOver;
		document.getElementById("nav_" + ids[i]).onmouseout = navOut;
	}
}