//simple function for switching visabiity of a div

function toggleLayer( whichLayer )
{
var elem, vis;
if( document.getElementById ) // this is the way the standards work
elem = document.getElementById( whichLayer ); 
else if( document.all ) // this is the way old msie versions work 
elem = document.all[whichLayer]; 
else if( document.layers ) // this is the way nn4 works 
elem = document.layers[whichLayer];  vis = elem.style;  // if the style.display value is blank we try to figure it out here
if(vis.display==''&&elem.offsetWidth!=undefined&&elem.offsetHeight!=undefined) 
vis.display = (elem.offsetWidth!=0&&elem.offsetHeight!=0)?'block':'none';  
vis.display = (vis.display==''||vis.display=='block')?'none':'block';
}

//functions for switching stylesheets and using cookies for persistence
//before a.disbaled to follow : alert(a.title)

function setActiveStyleSheet(title)
{
  var i, a, main;
  
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++)
  {
      if (a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title")) {
        
        a.disabled = true;

        if (a.getAttribute("title") == title) a.disabled = false;
        
      }
  }
      
}
  
function getActiveStyleSheet() {
  var i, a;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title") && !a.disabled) return a.getAttribute("title");
  }
  return null;
}

function getPreferredStyleSheet() {
  var i, a;
  for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1
       && a.getAttribute("rel").indexOf("alt") == -1
       && a.getAttribute("title")
       ) return a.getAttribute("title");
  }
  return null;
}

function createCookie(name,value,days) {
  if (days) {
    var date = new Date();
    date.setTime(date.getTime()+(days*24*60*60*1000));
    var expires = "; expires="+date.toGMTString();
  }
  else expires = "";
  document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
  var nameEQ = name + "=";
  var ca = document.cookie.split(';');
  for(var i=0;i < ca.length;i++) {
    var c = ca[i];
    while (c.charAt(0)==' ') c = c.substring(1,c.length);
    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
  }
  return null;
}

window.onload = function(e) {
  var cookie = readCookie("style");
  var title = cookie ? cookie : getPreferredStyleSheet();
  setActiveStyleSheet(title);
}

window.onunload = function(e) {
  var title = getActiveStyleSheet();
  createCookie("style", title, 365);
}

var cookie = readCookie("style");
var title = cookie ? cookie : getPreferredStyleSheet();
setActiveStyleSheet(title);