function layerVis(layerName) {
  layer=document.getElementById(layerName);
  
  if (layer.style.visibility=="visible") {
	layer.style.visibility="hidden";
  } else {
	layer.style.visibility="visible";
  }
}

function magicDrop(layerName) {
  layer=document.getElementById(layerName);
  layerContent=document.getElementById(layerName+"_contents");
  
  if (layer.style.visibility=="visible") {
	layer.style.width="0px";
	layer.style.height="0px";
	layer.style.visibility="hidden";
  } else {
	layer.style.width=layerContent.offsetWidth+"px";
	layer.style.height=layerContent.offsetHeight+"px";
	layer.style.visibility="visible";
  }
}

function toggleImage(imageName,img1,img2) {
  image=document.getElementById(imageName);
  bgStr=image.style.background;
  img1Pos=bgStr.indexOf(img1);
  img2Pos=bgStr.indexOf(img2);
  if (img1Pos>=0) {
    // set to img2
	image.style.background=bgStr.substr(0,img1Pos)+img2+")";
  } else if (img2Pos>=0) {
    // set to img1
	image.style.background=bgStr.substr(0,img2Pos)+img1+")";
  }
}

function toggleText(layerName,text1,text2) {
  layer=document.getElementById(layerName);
  if (layer.innerHTML==text1) {
    // set to text2
	layer.innerHTML=text2;
  } else if (layer.innerHTML==text2) {
    // set to text1
	layer.innerHTML=text1;
  }
}