/* Transition Function */

ie5 = (document.all && document.getElementById); 
ns6 = (!document.all && document.getElementById); 
var opac = 0; 	// default opacity set to 0
var vSetIntervalId = "";// setInterval funtion handler
var vEffectCnt = 0;
var vNext=1;
var vTotalObj=3;
var firstTime=1;

/* ==============================================================================
     Function : chgContent
     Parameter: vObjFrom - Base object currently displayed
		vObjTo   - Hidden object to be displayed
     Behaviour: Applies FadeOut / Fade In effect to base object
   ============================================================================== */

/* Only for temporary, to disable auto change of banner*/

function chgContent(){
	vObjFrom='spotBlk1';
	vObjTo='spotBlk'+vNext;
	if(vEffectCnt==0){     //check if FadeOut needs to be called
		vNext++;
		if(vNext>vTotalObj){
			vNext=2;
			vObjTo='spotBlk2';
		}
		window.clearInterval(vSetIntervalId);
		if(firstTime)
			vSetIntervalId=window.setInterval("fadeOut('"+vObjFrom+"','"+vObjTo+"')", 10240);			
		else
			vSetIntervalId=window.setInterval("fadeOut('"+vObjFrom+"','"+vObjTo+"')", 60); 
		firstTime=0
	}else if(vEffectCnt==1){
		swapContent(vObjFrom, vObjTo, 0);
		vSetIntervalId=window.setInterval("fadeIn('"+vObjFrom+"','"+vObjTo+"')", 60);		
	}else{
		vEffectCnt=0;
		vSetIntervalId=window.setInterval("chgContent()", 10240);
	}
}

/* ==============================================================================
     Function : swapContent
     Parameter: vObjFrom - Base object currently displayed
		vObjTo   - Hidden object to be displayed
		vOpac - Opacity value
     Behaviour: Swaps content between hidden and base object &
                Sets opacity
   ============================================================================== */
function swapContent(vObjFrom, vObjTo, vOpac){
	vObjFrom=document.getElementById(vObjFrom);
	vObjTo=document.getElementById(vObjTo);
	var vTemp=vObjFrom.innerHTML;    // Temporary variable to swap content between objects
	opac=vOpac;
	if(ie5) vObjFrom.filters.alpha.opacity = opac; 
	if(ns6) vObjFrom.style.MozOpacity = opac/100; 
	vObjFrom.innerHTML=vObjTo.innerHTML;
	vObjTo.innerHTML=vTemp;
}
/* ==============================================================================
     Function : fadeout
     Parameter: vObjFrom - Base Object to apply FadeOut effect
		vObjTo   - Hidden Object to be returned to chgContent() function
     Behaviour: Applies FadeOut effect to object, 
                Once done kills the effect instance &
                Calls chgContent() function to change content
   ============================================================================== */

function fadeOut(vObjFrom, vObjTo){
	if(opac>0){ 
		opac-=10; 
		if(ie5) document.getElementById(vObjFrom).filters.alpha.opacity = opac; 
		if(ns6) document.getElementById(vObjFrom).style.MozOpacity = opac/100; 
	} else{
		window.clearInterval(vSetIntervalId);
		opac=0;
		vEffectCnt=1;
		chgContent(vObjFrom, vObjTo);
	}
}

/* ==============================================================================
     Function : fadeIn
     Parameter: vObj - Object to apply FadeIn effect
     Behaviour: Applies FadeIn effect to object, 
                Once done kills the effect instance
   ============================================================================== */

function fadeIn(vObjFrom, vObjTo){
	if(opac<100){ 
		opac+=10; 
		if(ie5) document.getElementById(vObjFrom).filters.alpha.opacity = opac; 
		if(ns6) document.getElementById(vObjFrom).style.MozOpacity = opac/100; 
	} else{
		window.clearInterval(vSetIntervalId);
		vEffectCnt=2;
		chgContent(vObjFrom, vObjTo);
	}
}