function toggleVis(div, checkbox) {
  
  var div_visible;
	
  switch(checkbox){
    case "true": 
      div_visible = true;
      break;
    case "false":
      div_visible = false;
      break;
    case "":
      if(document.getElementById(div).style.visibility=="hidden") {
        div_visible = true;
      } else {
        div_visible = false;
      }
      break;
    default:
      div_visible = !document.getElementById(checkbox).checked;
      break;
  }
	
  if(div_visible==false) {
    document.getElementById(div).style.visibility = "hidden";
    document.getElementById(div).style.display = "none";
  } else {
    document.getElementById(div).style.visibility = "visible";
    document.getElementById(div).style.display = "block";
  }
         
}
function toggleVisPM(div, image) {
  
  toggleVis(div, "");
  
  a = document.getElementById(div).style.visibility;
  if(a=="hidden") {
    i = "plus.gif";
  } else {
    i = "minus.gif";
  }
  
  document.getElementById(image).src = "images/"+i;
  
}