function opacity(id, opacStart, opacEnd, millisec) 
{ 
   var speed = Math.round(millisec / 100);
   var timer = 0;  
   if(opacStart > opacEnd)
   { 
      for(i = opacStart; i >= opacEnd; i--)
      { 
         setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed)); 
         timer++; 
      } 
   }
   else if(opacStart < opacEnd)
   { 
      for(i = opacStart; i <= opacEnd; i++) 
      { 
         setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed)); 
         timer++; 
      } 
   } 
}

function changeOpac(opacity, id)
{ 
   var object = document.getElementById(id).style; 
   object.opacity = (opacity / 100); 
   object.MozOpacity = (opacity / 100); 
   object.KhtmlOpacity = (opacity / 100); 
   object.filter = "alpha(opacity=" + opacity + ")"; 
} 

function shiftOpacity(id, millisec)
{  
   if(document.getElementById(id).style.opacity == 0)
   {opacity(id, 0, 99, millisec);}
   else
   {opacity(id, 99, 0, millisec);} 
}