//
var TimerID = -1;
var Time = 0;
var TimeDelta = 100; // msec
//
var fTimeDelta = TimeDelta / 1000.0;
var fTransitionPeriod = TransitionPeriod/1000.0;
var fTotalPeriod = TotalDuration/1000.0;
//
var isIE;

 if (navigator.appName == "Netscape") 
   {
	    isiE = false;
   }
 else
   {
	    isIE = true;
   }

//---------------------------------------------------------------
function startclock() 
{
 tick();
}
//---------------------------------------------------------------
function tick ()
{
     Time += fTimeDelta;
	 
	 if (Time > TotalFullDuration)
	     Time = 0.0;
		 	 
	 for (n = 0; n < NumElements; n++)
	    {
		 num_slides = NumSlides[n];
		 tStart     = TOffSets[n];
		 idn        = 'img_' + n;
		 
	     for (m = 0; m < num_slides; m++)
		    {
		     tEnd = tStart + fTransitionPeriod;
		 
	         if ((Time >= tStart) && (Time <= tEnd))
		        {
			     a = ((Time - tStart) / fTransitionPeriod).toFixed(3);
			  
		         if (m == 0)
		            {
				     idp = idn + '_' + (num_slides-1);
			        }
		         else
		            {
				     idp = idn + '_' + (m-1);
			        }
				 idc = idn + '_' + m;
		         ip  = document.getElementById(idp);
		         ic  = document.getElementById(idc);
				 
			     if (!isIE)
			        {
                     ic.style.opacity = a;
			         ip.style.opacity = 1.0-a;
				    }
			     else
			        {
                     ic.filters.alpha.opacity=(100*a).toFixed(0);
                     ip.filters.alpha.opacity=(100*(1.0-a)).toFixed(0);
				    }
			   }
		     tStart += fTotalPeriod;
			}
		}	 
	 TimerID = setTimeout ("tick()", TimeDelta);
}
//---------------------------------------------------------------
function stopclock ()
{
	if (TimerID != -1)
	   {
        clearTimeout(TimerID);
		TimerID = -1;
	   }
}