var img1 = new Image();
img1.src = "images/plus.gif";
var img2 = new Image();
img2.src = "images/minus.gif";

function animateMenu(e) {
  var srcId, srcElement, targetElement;
  srcElement = window.event.srcElement;
  if ((srcElement.className.toUpperCase() == "LEVEL1") && (srcElement.id != "")) {
		srcID = srcElement.id.substr(0, srcElement.id.length-1);
		targetElement = document.all(srcID + "s");
		srcElement = document.all(srcID + "i");

		if (targetElement.style.display == "none") {			
			targetElement.style.display = "";
		 	if (srcElement.className.toUpperCase() == "LEVEL1") srcElement.src = img2.src;
		} else {
			targetElement.style.display = "none";
			if (srcElement.className.toUpperCase() == "LEVEL1") srcElement.src = img1.src;
		}
  }
}