var fade_started=0;

function fadeTrans(id1, id2, t1)
{
  if(fade_started==0)
  {
    fade_started=1;
    opacity(id1,100,0,t1);
    setTimeout("fadeTrans('"+id1+"', '"+id2+"', "+t1+")",t1);
  }
  else
  {
    document.getElementById(id1).src = document.getElementById(id2).src;
    opacity(id1, 0, 100, t1);
    setTimeout("fadeTransComplete()",t1);
  }
}

function fadeTransComplete()
{
  fade_started=0;
}

function opacity(id,opacStart,opacEnd,millisec)
{
    //speed for each frame
    var speed = Math.round( millisec / 100 );
    var timer = 0;
    
    //determine the direction for the blending, if start and end are the same nothing happens
    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 / 10 );
    object.MozOpacity = (opacity / 10 );
    object.filter = "alpha(opacity=" + opacity + ")";
}