var cname = 'element=';
var ca = document.cookie.split(';');
var element = '';

for(var i = 0; i < ca.length; i++) 
{
   var str = ca[i];
   var indx = str.indexOf(cname);
   if (indx >= 0)
   {
      element = str.substring(cname.length + indx, str.length);
      break;
   }
}

function bg_fire()
{
   document.body.style.backgroundColor = "rgb(255, 187, 0)";
   document.body.style.backgroundImage = 'url("bg_fire.jpg")';
}

function bg_water()
{
   document.body.style.backgroundColor = "rgb(0, 68, 255)";
   document.body.style.backgroundImage = 'url("bg_water.jpg")';
}

function bg_earth()
{
   document.body.style.backgroundColor = "rgb(181, 87, 44)";
   document.body.style.backgroundImage = 'url("bg_earth.jpg")';
}

function bg_air()
{
   document.body.style.backgroundColor = "rgb(74, 168, 211)";
   document.body.style.backgroundImage = 'url("bg_air.jpg")';
}

if (element == 'fire') window.onload = bg_fire;
else if (element == 'water') window.onload = bg_water;
else if (element == 'earth') window.onload = bg_earth;
else if (element == 'air') window.onload = bg_air;
else
{
   if (Math.random() < 0.5)
   {
      window.onload = bg_fire;
      element = 'undef_fire';
   }
   else
   {
      window.onload = bg_water;
      element = 'undef_water';
   }
}

function cycle_bg()
{
   switch (element)
   {
      case 'fire':
      case 'undef_fire':
         bg_water();
         element = 'water';
         document.cookie = cname+'water; path=/';
         break;

      case 'water':
      case 'undef_water':
         bg_earth();
         element = 'earth';
         document.cookie = cname+'earth; path=/';
         break;
      
      case 'earth':
         bg_air();
         element = 'air';
         document.cookie = cname+'air; path=/';
         break;
         
      case 'air':
         bg_fire();
         element = 'fire';
         document.cookie = cname+'fire; path=/';
         break;
   }
}