var imgScroller = null;

var selectedLink="1";

function initImageScroller(numItems, width, startingIndex, animationSpeed, sectionPreID, shortcutPreID, contentID)
{
	
	var rand_no = Math.floor((numItems)*Math.random()) + 1;
	startingIndex = rand_no;	// comment this out if you don't want random index
	
	var totalWidth = 800 * (numItems+2);
	var tempMarginLeft = startingIndex * -800;
	
	

	
	document.getElementById('moving_content').style.width = '' + totalWidth + 'px';
	document.getElementById('moving_content').style.marginLeft = '' + tempMarginLeft + 'px';
	document.getElementById(sectionPreID + startingIndex).style.visibility = "visible";
	
    var xPos = new Array();
    var sections = new Array();
    var shortcuts = new Array();
    for ( var i = 0; i < numItems+2; i++ )
    {
        xPos[i] = 0 - i*width;   // -800, -1600, etc 
        var sectionID = sectionPreID + (i); 
		sections[i] = document.getElementById(sectionID);
		
		if ( i < numItems ) 
		{
		    var shortcutID = shortcutPreID + (i);
		    shortcuts[i] = document.getElementById(shortcutID);
		}
	}	
    
        
    imgScroller = 
    {   
        "numItems":         numItems, 
        "animationSpeed":   animationSpeed,
        "animating":        false,
        "currentIndex":     startingIndex, 
        "xPos":             xPos,
        "sectionObjects":   sections,
        "object":           document.getElementById('moving_content')
    };
}




function ScrollTo(val)
{
    // val is either an increment (+1/-1) or an ID
	if(!imgScroller.animating)
	{	    
	    imgScroller.currentIndex = parseInt(imgScroller.currentIndex) + val;

	    imgScroller.animating = true;
	    ToggleAnimationItems(1);
	    AnimateScroll();
	}
}

function AnimateScroll()
{
    if ( !imgScroller.object )
    {
        ToggleAnimationItems(false);
        return;
    }
        
	var xLeft = imgScroller.object.style.marginLeft;
	if (xLeft.indexOf('px') > 0) {
		xLeft = parseInt(xLeft.substring(0, xLeft.length - 2));
	}
	
	/* 
	Test Piece
	if ( imgScroller.currentIndex == 2 && xLeft == '' )
		xLeft = -2400;
	*/
	
	
	var newX = (xLeft + imgScroller.xPos[imgScroller.currentIndex])/2;
	imgScroller.object.style.marginLeft=newX+'px'
	var checkVal = imgScroller.xPos[imgScroller.currentIndex];
	if(checkVal-5 <= newX && newX <=checkVal+5)
	{   
		imgScroller.animating=false;
		imgScroller.object.style.marginLeft = imgScroller.xPos[imgScroller.currentIndex]+'px';
        CheckAtEdge();		
		ToggleAnimationItems(0);
	}
	else
		setTimeout("AnimateScroll()", imgScroller.animationSpeed);
	
}


function CheckAtEdge()
{
    if ( imgScroller.currentIndex > imgScroller.numItems )
    {
        // too large, wrap it around
        imgScroller.currentIndex = 1;
        imgScroller.object.style.marginLeft = imgScroller.xPos[1]+'px';
    }
    
    if ( imgScroller.currentIndex <= 0 )
    {
        // too small, wrap it around
        imgScroller.currentIndex = imgScroller.numItems;
        imgScroller.object.style.marginLeft = imgScroller.xPos[imgScroller.numItems]+'px';
    }
}


function ToggleAnimationItems(isOn)
{
    for ( var i = 0; i <= imgScroller.numItems+1; i++ )
    {
        if ( isOn == 1 )
            imgScroller.sectionObjects[i].style.visibility='visible';
		else
		    if(i!=imgScroller.currentIndex)
			    imgScroller.sectionObjects[i].style.visibility='hidden';
		    
		
	}
}