//Offer page horizontal scroll menu for games

var scrollIncrement = 12;
var scrollPosition = new Array(0, 0);
var scrollTimer;

function containerWidth(targetIndex){
	var centerContainerObj = document.getElementById('centerContainer' + targetIndex);
  var widthValue = 0;		
		
	if(centerContainerObj.offsetWidth){ 
       widthValue=centerContainerObj.offsetWidth; 
  } 
  else if(centerContainerObj.style.pixelWidth){ 
       widthValue=centerContainerObj.style.pixelWidth; 
  } 
  
  return widthValue;
}

function scrollingRight(targetIndex){
	var gamesObj = document.getElementById('gamesContainer' + targetIndex);
	var endMarkerObj = document.getElementById('endMarker' + targetIndex);
	var buttonRightObj = document.getElementById('buttonNavRight' + targetIndex);
	var buttonLeftObj = document.getElementById('buttonNavLeft' + targetIndex);
	
	//not at the end of the list, scroll right
	if ((scrollPosition[targetIndex] + containerWidth(targetIndex) + scrollIncrement) < endMarkerObj.offsetLeft){
		scrollPosition[targetIndex] = scrollPosition[targetIndex] + scrollIncrement;
		gamesObj.style.left = (scrollPosition[targetIndex]*-1) + 'px';
		scrollTimer = setTimeout('scrollingRight(' + targetIndex + ')', 33);	
		
		buttonLeftObj.className = 'buttonNavLeft';
	}
	
	//at the end of the list
	else{
		if (endMarkerObj.offsetLeft > containerWidth(targetIndex)){
			scrollPosition[targetIndex] = endMarkerObj.offsetLeft - containerWidth(targetIndex);
			gamesObj.style.left = (scrollPosition[targetIndex]*-1) + 'px';
		}
		
		buttonRightObj.className = 'buttonNavRight navRightInactive';
	}
}

function scrollingLeft(targetIndex){
	var gamesObj = document.getElementById('gamesContainer' + targetIndex);
	var buttonRightObj = document.getElementById('buttonNavRight' + targetIndex);
	var buttonLeftObj = document.getElementById('buttonNavLeft' + targetIndex);
	
	//at the beginning of the list
	if (scrollPosition[targetIndex] - scrollIncrement <= 0){
		scrollPosition[targetIndex] = 0;
		gamesObj.style.left = '0px';
		
		buttonLeftObj.className = 'buttonNavLeft navLeftInactive';
	}
	
	//not at the beginning of the list, scroll left
	else{
		scrollPosition[targetIndex] = scrollPosition[targetIndex] - scrollIncrement;
		gamesObj.style.left = (scrollPosition[targetIndex]*-1) + 'px';
		scrollTimer = setTimeout('scrollingLeft(' + targetIndex + ')', 33);	
		
		buttonRightObj.className = 'buttonNavRight';
	}
}

function scrollingStop(){
	clearTimeout(scrollTimer);
}